diff --git a/Doc/Sd1/languageFundamentals.xml b/Doc/Sd1/languageFundamentals.xml
index 0a5981f872e9fc0b15a2dde55af041c423c49aa2..bddb6344e136062bd4c39913cad5a24633953e8e 100644
--- a/Doc/Sd1/languageFundamentals.xml
+++ b/Doc/Sd1/languageFundamentals.xml
@@ -325,8 +325,8 @@ X X X X X</programlisting>
<programlisting language="java">double pi;</programlisting>
</figure>
- <para>We may assign values to variables or build expressions like <code language="java">pi
- * 2.0 * 2.0</code> :</para>
+ <para>We may assign values to variables or build expressions like <code
+ language="java">pi * 2.0 * 2.0</code> :</para>
<figure xml:id="sd1_fig_varDeclareAndUse">
<title>Declare and use</title>
@@ -394,13 +394,14 @@ int c;</programlisting>
<itemizedlist>
<listitem>
- <para>Start with a small letter like <code language="java">africa</code> rather than
- <code language="java">Africa</code>.</para>
+ <para>Start with a small letter like <code
+ language="java">africa</code> rather than <code
+ language="java">Africa</code>.</para>
</listitem>
<listitem>
- <para>Use <quote>camel case</quote> e.g.
- <code language="java">myFirstCode</code>.</para>
+ <para>Use <quote>camel case</quote> e.g. <code
+ language="java">myFirstCode</code>.</para>
<mediaobject>
<imageobject>
@@ -410,7 +411,8 @@ int c;</programlisting>
</listitem>
<listitem>
- <para>Do not start with <code language="java">_</code> or <code language="java">$</code>.</para>
+ <para>Do not start with <code language="java">_</code> or <code
+ language="java">$</code>.</para>
</listitem>
</itemizedlist>
</figure>
@@ -444,14 +446,15 @@ pi = 1.0; // Compile time error: Constant cannot be modified</programlisting>
<tr>
<td><itemizedlist>
<listitem>
- <para>Start with a letter, <quote><code language="java">_</code></quote> or
- <quote><code language="java">$</code></quote></para>
+ <para>Start with a letter, <quote><code
+ language="java">_</code></quote> or <quote><code
+ language="java">$</code></quote></para>
</listitem>
<listitem>
<para><emphasis role="bold">May</emphasis> be followed by
- letters, digits, <quote><code language="java">_</code></quote> or
- <quote><code language="java">$</code></quote></para>
+ letters, digits, <quote><code language="java">_</code></quote>
+ or <quote><code language="java">$</code></quote></para>
</listitem>
<listitem>
@@ -464,8 +467,9 @@ pi = 1.0; // Compile time error: Constant cannot be modified</programlisting>
</listitem>
<listitem>
- <para><quote><code language="java">boolean</code></quote> or
- <quote><code language="java">null</code></quote> literal</para>
+ <para><quote><code language="java">boolean</code></quote>
+ or <quote><code language="java">null</code></quote>
+ literal</para>
</listitem>
</itemizedlist>
</listitem>
@@ -491,7 +495,8 @@ pi = 1.0; // Compile time error: Constant cannot be modified</programlisting>
<td valign="top"><itemizedlist>
<listitem>
- <para><code language="java"><emphasis role="red">2sad</emphasis></code></para>
+ <para><code language="java"><emphasis
+ role="red">2sad</emphasis></code></para>
</listitem>
<listitem>
@@ -500,7 +505,8 @@ pi = 1.0; // Compile time error: Constant cannot be modified</programlisting>
</listitem>
<listitem>
- <para><code language="java"><emphasis role="red">true</emphasis></code></para>
+ <para><code language="java"><emphasis
+ role="red">true</emphasis></code></para>
</listitem>
</itemizedlist></td>
</tr>
@@ -758,8 +764,8 @@ System.out.println(count + ":" + Count);</programlisting>
<td>yes</td>
- <td><code language="java">println</code> is a method of
- <code language="java">System.out.println(...)</code> but is no <xref
+ <td><code language="java">println</code> is a method of <code
+ language="java">System.out.println(...)</code> but is no <xref
linkend="glo_Java"/> keyword.</td>
</tr>
@@ -1000,18 +1006,19 @@ int i = d; // Error: Incompatible types</programlisting>
<answer>
<para>The first snippet compiles by using the <emphasis
- role="bold">widening conversion</emphasis>: When assigning <code language="java">d
- = i</code> the <xref linkend="glo_Java"/> compiler implicitly
- converts the <code language="java"
+ role="bold">widening conversion</emphasis>: When assigning <code
+ language="java">d = i</code> the <xref linkend="glo_Java"/>
+ compiler implicitly converts the <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
into a <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
value.</para>
<para>Turning a double into an int is more cumbersome: The
- expression <code language="java">i = 3.5</code> could be evaluated by agreeing on
- a specific rounding prescription. But what about i =
- 3457357385783573478955345.45? A <xref linkend="glo_Java"/> <code language="java"
+ expression <code language="java">i = 3.5</code> could be evaluated
+ by agreeing on a specific rounding prescription. But what about i
+ = 3457357385783573478955345.45? A <xref linkend="glo_Java"/> <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>'s
maximum value is <inlineequation>
<m:math display="inline">
@@ -1331,7 +1338,8 @@ int i = (int) d; // Explicit cast double to int</programlisting>
<para>In 3-bit two complement representation the
leftmost bit will be discarded. Thus the actual result
- is <code language="java">101</code> as being expected.</para>
+ is <code language="java">101</code> as being
+ expected.</para>
</glossdef>
</glossentry>
@@ -1437,13 +1445,15 @@ int i = (int) d; // Explicit cast double to int</programlisting>
</tr>
<tr>
- <td><code language="java">00000000_00000000_00000000_00000000</code></td>
+ <td><code
+ language="java">00000000_00000000_00000000_00000000</code></td>
<td>0</td>
</tr>
<tr>
- <td><code language="java">01111111_11111111_11111111_11111111</code></td>
+ <td><code
+ language="java">01111111_11111111_11111111_11111111</code></td>
<td><inlineequation>
<m:math display="inline">
@@ -1469,7 +1479,8 @@ int i = (int) d; // Explicit cast double to int</programlisting>
</tr>
<tr>
- <td><code language="java">10000000_00000000_00000000_00000000</code></td>
+ <td><code
+ language="java">10000000_00000000_00000000_00000000</code></td>
<td><inlineequation>
<m:math display="inline">
@@ -1493,21 +1504,24 @@ int i = (int) d; // Explicit cast double to int</programlisting>
</tr>
<tr>
- <td><code language="java">11111111_11111111_11111111_11111111</code></td>
+ <td><code
+ language="java">11111111_11111111_11111111_11111111</code></td>
<td>-1</td>
</tr>
</table>
<para>Use <link
- xlink:href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.1"><code language="java"
+ xlink:href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.1"><code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
literals</link> in <link
xlink:href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-BinaryNumeral">binary
- representation</link> like e.g. <code language="java">0B1100</code> in the
- <quote>Language Fundamentals</quote> / <quote>Literals</quote>
- section of <xref linkend="bib_Kurniawan2015"/> in order to write
- an <code language="java"
+ representation</link> like e.g. <code
+ language="java">0B1100</code> in the <quote>Language
+ Fundamentals</quote> / <quote>Literals</quote> section of <xref
+ linkend="bib_Kurniawan2015"/> in order to write an <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>'s
minimum and maximum possible value to standard output.</para>
@@ -1538,7 +1552,8 @@ int i = (int) d; // Explicit cast double to int</programlisting>
}</programlisting>
<para>BTW: The <xref linkend="glo_JDK"/> does provide maximum
- value, minimum value and related information for <code language="java"
+ value, minimum value and related information for <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-E">char</code>,
<code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-A">byte</code>,
@@ -1746,8 +1761,9 @@ int a = 20,
<para>The above code does not compile due to a compiler error when
defining variable <code language="java">c</code>.</para>
- <para>Explain the underlying cause. In particular: Why is <code language="java">b
- = 03</code> just fine in contrast to <code language="java">c = 09</code> ?</para>
+ <para>Explain the underlying cause. In particular: Why is <code
+ language="java">b = 03</code> just fine in contrast to <code
+ language="java">c = 09</code> ?</para>
<tip>
<para>Re-read the section on integer literal
@@ -1775,8 +1791,8 @@ int a = 20,
<programlisting language="java">int a = 041;
System.out.println("Value = " + a);</programlisting>
- <para>On execution we receive the output <code language="java">Value = 33</code>.
- Explain this result</para>
+ <para>On execution we receive the output <code
+ language="java">Value = 33</code>. Explain this result</para>
</question>
<answer>
@@ -1820,8 +1836,8 @@ System.out.println("Value = " + a);</programlisting>
<tip>
<para>Try to assign the corresponding int values like e.g.
- <code language="java">0x27BD</code> rather than using the symbol
- itself.</para>
+ <code language="java">0x27BD</code> rather than using the
+ symbol itself.</para>
</tip>
</listitem>
@@ -1836,19 +1852,21 @@ System.out.println("Value = " + a);</programlisting>
<orderedlist>
<listitem>
<para>Our emoticon's decimal <xref linkend="glo_unicode"/>
- value is 128,526 or hexadecimal <code language="java">1f60E</code> . So its
- value is larger than 65535 and thus requires more than two
- bytes. <xref linkend="glo_Java"/> however represents
- characters using just two bytes. Thus the emoticon does not
- fit into a single <xref linkend="glo_Java"/> <code language="java">char</code>
+ value is 128,526 or hexadecimal <code
+ language="java">1f60E</code> . So its value is larger than
+ 65535 and thus requires more than two bytes. <xref
+ linkend="glo_Java"/> however represents characters using just
+ two bytes. Thus the emoticon does not fit into a single <xref
+ linkend="glo_Java"/> <code language="java">char</code>
value:</para>
<programlisting language="java">char c = 0x1f60e; // Error: Incompatible types
// Required: char Found: int</programlisting>
<para>On contrary the arrow's decimal value of 10173 or
- hexadecimal <code language="java">0x27BD</code> fits perfectly well into a
- <xref linkend="glo_Java"/> <code language="java">char</code> variable:</para>
+ hexadecimal <code language="java">0x27BD</code> fits perfectly
+ well into a <xref linkend="glo_Java"/> <code
+ language="java">char</code> variable:</para>
<programlisting language="java">char c = 0x27BD;
System.out.println("Arrow: " + c);
@@ -2175,51 +2193,59 @@ Value 4: 29</screen>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-E">char</code></td>
- <td><code language="java">'A'</code>, <code language="java">'\u0041'</code></td>
+ <td><code language="java">'A'</code>, <code
+ language="java">'\u0041'</code></td>
</tr>
<tr>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code></td>
- <td><code language="java">29</code>, <code language="java">0b1_1101</code>, <code language="java">0x1D</code>,
- <code language="java">035</code>, <code language="java">-29</code>,</td>
+ <td><code language="java">29</code>, <code
+ language="java">0b1_1101</code>, <code language="java">0x1D</code>,
+ <code language="java">035</code>, <code
+ language="java">-29</code>,</td>
</tr>
<tr>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code></td>
- <td><code language="java">35<emphasis role="red">L</emphasis></code>,
- <code language="java">0b10_0011<emphasis role="red">L</emphasis></code>,
+ <td><code language="java">35<emphasis
+ role="red">L</emphasis></code>, <code
+ language="java">0b10_0011<emphasis role="red">L</emphasis></code>,
<code language="java">0x23<emphasis role="red">L</emphasis></code>,
<code language="java">043<emphasis role="red">L</emphasis></code>,
- <code language="java">-35<emphasis role="red">L</emphasis></code>,...</td>
+ <code language="java">-35<emphasis
+ role="red">L</emphasis></code>,...</td>
</tr>
<tr>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">float</code></td>
- <td><code language="java">55.43<emphasis role="red">F</emphasis></code>,
- <code language="java">1.7E-23<emphasis role="red">F</emphasis></code>,
+ <td><code language="java">55.43<emphasis
+ role="red">F</emphasis></code>, <code
+ language="java">1.7E-23<emphasis role="red">F</emphasis></code>,
<code language="java">-17.<emphasis role="red">F</emphasis></code>,
- <code language="java">100_342.334_113<emphasis role="red">F</emphasis></code></td>
+ <code language="java">100_342.334_113<emphasis
+ role="red">F</emphasis></code></td>
</tr>
<tr>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code></td>
- <td><code language="java">55.43</code>, <code language="java">1.7 E -23</code>,
- <code language="java">-17.</code></td>
+ <td><code language="java">55.43</code>, <code language="java">1.7 E
+ -23</code>, <code language="java">-17.</code></td>
</tr>
<tr>
<td><code language="java"
xlink:href="https://docs.oracle.com/javase/tutorial/java/data/strings.html">String</code></td>
- <td><code language="java">"Hello"</code>, <code language="java">"Greek Δ"</code>, <code language="java">"Greek <link
+ <td><code language="java">"Hello"</code>, <code
+ language="java">"Greek Δ"</code>, <code language="java">"Greek <link
xlink:href="https://www.fileformat.info/info/unicode/char/0394/index.htm">\u0394</link>"</code></td>
</tr>
@@ -2252,10 +2278,11 @@ Value 4: 29</screen>
xlink:href="http://www.rapidtables.com/code/text/ascii-table.htm#print">printable
ASCII characters</link>. Write a <xref linkend="glo_Java"/>
application by starting just from from the character literals
- <code language="java">' '</code>, <code language="java">'!'</code>, <code language="java">'"'</code>,
- <code language="java">'#'</code>, '$', '%', '&' to show their corresponding
- <xref linkend="glo_ASCII"/> decimal values. The intended output
- is:</para>
+ <code language="java">' '</code>, <code
+ language="java">'!'</code>, <code language="java">'"'</code>,
+ <code language="java">'#'</code>, '$', '%', '&' to show their
+ corresponding <xref linkend="glo_ASCII"/> decimal values. The
+ intended output is:</para>
<screen> : 32
!: 33
@@ -2271,7 +2298,8 @@ $: 36
<tip>
<para>A <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-E">char</code>
- value being represented by two bytes may be assigned to an <code language="java"
+ value being represented by two bytes may be assigned to an <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
variable.</para>
</tip>
@@ -2532,10 +2560,10 @@ Decimal:932</screen>
linkend="sw1QandaMaxMinInt">related int example</link>
accordingly:</para>
- <programlisting language="java">short minumum = 0B10000000_00000000,
+ <programlisting language="java">short minimum = 0B10000000_00000000, // short: two byte two-complement
maximum = 0B01111111_11111111;
-System.out.println("Minimum short value:" + minumum);
+System.out.println("Minimum short value:" + minimum);
System.out.println("Maximum short value:" + maximum</programlisting>
<para>Our programmer is baffled:</para>
@@ -2551,7 +2579,8 @@ System.out.println("Maximum short value:" + maximum</programlisting>
</listitem>
<listitem>
- <para>On contrary the second assignment <code language="java">maximum = 0B01111111_11111111</code> gets
+ <para>On contrary the second assignment <code
+ language="java">maximum = 0B01111111_11111111</code> gets
smoothly accepted.</para>
</listitem>
</itemizedlist>
@@ -2566,8 +2595,8 @@ System.out.println("Maximum short value:" + maximum</programlisting>
<answer>
<para>Since variables of type <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- have a two bytes representation their corresponding range is
- <inlineequation>
+ are signed having a two byte two complement representation their
+ corresponding range is <inlineequation>
<m:math display="inline">
<m:mrow>
<m:mo>[</m:mo>
@@ -2604,24 +2633,90 @@ System.out.println("Maximum short value:" + maximum</programlisting>
</inlineequation>. Thus intensity values ranging from 0 to 255
will be easily accommodated.</para>
- <para>The second question is more difficult to explain: The <xref
+ <para>In fact using a <code language="java">byte</code> might be
+ sufficient as well: Our programmer simply needs to map the
+ intended intensity values <inlineequation>
+ <m:math display="inline">
+ <m:mrow>
+ <m:mo>[</m:mo>
+
+ <m:mrow>
+ <m:mi>0</m:mi>
+
+ <m:mo>,</m:mo>
+
+ <m:mrow>
+ <m:msup>
+ <m:mi>2</m:mi>
+
+ <m:mi>8</m:mi>
+ </m:msup>
+
+ <m:mo>-</m:mo>
+
+ <m:mi>1</m:mi>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mo>]</m:mo>
+ </m:mrow>
+ </m:math>
+ </inlineequation> to a <code language="java">byte</code>'s range
+ of <inlineequation>
+ <m:math display="inline">
+ <m:mrow>
+ <m:mo>[</m:mo>
+
+ <m:mrow>
+ <m:mrow>
+ <m:mo>-</m:mo>
+
+ <m:msup>
+ <m:mi>2</m:mi>
+
+ <m:mi>7</m:mi>
+ </m:msup>
+ </m:mrow>
+
+ <m:mo>,</m:mo>
+
+ <m:mrow>
+ <m:msup>
+ <m:mi>2</m:mi>
+
+ <m:mi>7</m:mi>
+ </m:msup>
+
+ <m:mo>-</m:mo>
+
+ <m:mi>1</m:mi>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mo>]</m:mo>
+ </m:mrow>
+ </m:math>
+ </inlineequation>.</para>
+
+ <para>The second question is more difficult to answer: The <xref
linkend="glo_Java"/> standard only defines <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
- literals. It does however not define <code language="java"
+ but no <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- (or <code language="java"
- xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-A">byte</code>)
+ or <code language="java"
+ xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-A">byte</code>
literals.</para>
- <para>Thus the 0B01111111_11111111 literal will be treated as an
+ <para>Thus our 0B01111111_11111111 literal will be treated as an
<code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
- value being compatible with a <code language="java"
+ value being assignable to a <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- variable and is thus assignable.</para>
+ variable.</para>
- <para>On the contrary the binary value
- <code language="java">10000000_00000000</code> evaluates to <inlineequation>
+ <para>On the contrary the binary <code language="java">int</code>
+ value <code language="java">10000000_00000000</code> evaluates to
+ <inlineequation>
<m:math display="inline">
<m:msup>
<m:mn>2</m:mn>
@@ -2629,13 +2724,28 @@ System.out.println("Maximum short value:" + maximum</programlisting>
<m:mi>15</m:mi>
</m:msup>
</m:math>
- </inlineequation> (equal to 32768) exceeding a two-byte (signed)
- short variable's upper limit.</para>
+ </inlineequation> (equal to 32768) rather then being interpreted
+ as a two byte two complement <code language="java">short</code>.
+ It thus exceeds a <code language="java">short</code> variable's
+ upper limit being totally different from the intended two-byte two
+ complement short value of <inlineequation>
+ <m:math display="inline">
+ <m:mrow>
+ <m:mo>-</m:mo>
+
+ <m:msup>
+ <m:mi>2</m:mi>
+
+ <m:mi>15</m:mi>
+ </m:msup>
+ </m:mrow>
+ </m:math>
+ </inlineequation>.</para>
<para>Even worse: A <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- variable containing binary <code language="java">10000000_00000000</code> due to
- its two byte <link
+ variable containing binary <code
+ language="java">10000000_00000000</code> due to its two byte <link
xlink:href="https://en.wikipedia.org/wiki/Two's_complement#firstHeading">Two's
complement</link> representation has got a value <inlineequation>
<m:math display="inline">
@@ -2651,10 +2761,22 @@ System.out.println("Maximum short value:" + maximum</programlisting>
</m:math>
</inlineequation> (or -32768).</para>
- <para>In order to avoid this error we need an explicit type
- conversion (a so called cast):</para>
+ <para>Avoiding this error requires the value <inlineequation>
+ <m:math display="inline">
+ <m:mrow>
+ <m:mo>-</m:mo>
+
+ <m:msup>
+ <m:mn>2</m:mn>
- <programlisting language="java">short minumum = (short) 0B10000000_00000000;</programlisting>
+ <m:mi>15</m:mi>
+ </m:msup>
+ </m:mrow>
+ </m:math>
+ </inlineequation> in <code language="java">int</code>
+ notation:</para>
+
+ <programlisting language="java">short minumum = 0B11111111_11111111_10000000_00000000;</programlisting>
<para>Since a <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
@@ -2692,14 +2814,20 @@ System.out.println("Maximum short value:" + maximum</programlisting>
<m:mo>]</m:mo>
</m:mrow>
</m:math>
- </inlineequation> we may as well use a unary minus sign
- instead:</para>
+ </inlineequation> we may as well use int <inlineequation>
+ <m:math display="inline">
+ <m:msup>
+ <m:mn>2</m:mn>
+
+ <m:mi>15</m:mi>
+ </m:msup>
+ </m:math>
+ </inlineequation> adding a unary minus sign:</para>
<programlisting language="java">short minumum = -0B10000000_00000000;</programlisting>
<para>Both variants are syntactically correct and will thus
- compile. However they are likely not being intended by our
- programmer.</para>
+ compile.</para>
<para>The error in the first place is probably assigning a value
of <inlineequation>
@@ -2716,15 +2844,16 @@ System.out.println("Maximum short value:" + maximum</programlisting>
</m:math>
</inlineequation> to a <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- variable at all.</para>
+ variable mixing two- and four-byte two-complement
+ representation.</para>
</answer>
</qandaentry>
</qandadiv>
</qandaset>
<qandaset defaultlabel="qanda" xml:id="sd1QandaBracesInPrintln">
- <title>Why using braces inside <code language="java">System.out.println(...)</code>
- ?</title>
+ <title>Why using braces inside <code
+ language="java">System.out.println(...)</code> ?</title>
<qandadiv>
<qandaentry>
@@ -2812,16 +2941,18 @@ System.out.println("Decimal:" +<co linkends="sd1ListingPlusOpDuplicate-1"
<callout arearefs="sd1ListingPlusOpDuplicate-1-co"
xml:id="sd1ListingPlusOpDuplicate-1">
<para><quote>+</quote> operator concatenating the two strings
- <code language="java">"Decimal:"</code> and <code language="java">"932"</code>.</para>
+ <code language="java">"Decimal:"</code> and <code
+ language="java">"932"</code>.</para>
</callout>
<callout arearefs="sd1ListingPlusOpDuplicate-2-co sd1ListingPlusOpDuplicate-3-co sd1ListingPlusOpDuplicate-4-co sd1ListingPlusOpDuplicate-5-co"
xml:id="sd1ListingPlusOpDuplicate-2">
<para><quote>+</quote> operators computing the integer sum of
512, 256, 128, 32 and 4 yielding a value of 932. This value
- subsequently gets transformed into the String
- <code language="java">"932"</code> in order to be compatible with the
- preceding <code language="java">"Decimal:"</code> string.</para>
+ subsequently gets transformed into the String <code
+ language="java">"932"</code> in order to be compatible with
+ the preceding <code language="java">"Decimal:"</code>
+ string.</para>
</callout>
</calloutlist>
</answer>
@@ -2848,9 +2979,9 @@ System.out.println("Decimal:" +<co linkends="sd1ListingPlusOpDuplicate-1"
<screen>3 Games having 22 players each results in 66 players altogether.</screen>
- <para>Write your code in a way that changing i.e. <code language="java">final int
- games = 4</code> will result in a corresponding change of
- output.</para>
+ <para>Write your code in a way that changing i.e. <code
+ language="java">final int games = 4</code> will result in a
+ corresponding change of output.</para>
</question>
<answer>
@@ -2934,18 +3065,18 @@ System.out.println("Decimal:" +<co linkends="sd1ListingPlusOpDuplicate-1"
<itemizedlist>
<listitem>
- <para
- xlink:href="http://codingbat.com/prob/p171896">helloName</para>
+ <para><link
+ xlink:href="http://codingbat.com/prob/p171896">helloName</link></para>
</listitem>
<listitem>
- <para
- xlink:href="http://codingbat.com/prob/p161056">makeAbba</para>
+ <para><link
+ xlink:href="http://codingbat.com/prob/p161056">makeAbba</link></para>
</listitem>
<listitem>
- <para
- xlink:href="http://codingbat.com/prob/p147483">makeTags</para>
+ <para xlink:href="http://codingbat.com/prob/p147483"><link
+ xlink:href="http://codingbat.com/prob/p147483">makeTags</link></para>
</listitem>
</itemizedlist>
</question>
@@ -2991,8 +3122,9 @@ System.out.println("Character: " + arabicChar);</programlisting>
<answer>
<para>According to the <link
xlink:href="https://en.wikipedia.org/wiki/Arabic_(Unicode_block)#Block">Arabic
- block</link> table the code point of <code language="java">'ڜ'</code> is U+069C
- having a decimal equivalent of 1692.</para>
+ block</link> table the code point of <code
+ language="java">'ڜ'</code> is U+069C having a decimal equivalent
+ of 1692.</para>
<para><xref linkend="glo_Java"/> uses two bytes equivalent to 16
bits for representing positive <code language="java"
@@ -3018,8 +3150,8 @@ System.out.println("Character: " + arabicChar);</programlisting>
<m:mi>65535</m:mi>
</m:mrow>
</m:math>
- </inlineequation>. So <code language="java">'ڜ'</code> fits well into this
- range.</para>
+ </inlineequation>. So <code language="java">'ڜ'</code> fits well
+ into this range.</para>
<para>According to the <link
xlink:href="https://en.wikipedia.org/wiki/Emoticons_(Unicode_block)">Emoticons
@@ -3087,11 +3219,12 @@ _____________________________________
</figure>
<para>This exceeds the four byte limit of int variables. Thus the leading
- <quote>1</quote> will be discarded leaving us with a result of
- <code language="java">11111111_11111111_11111111_11111110</code> equalling -2 with respect
- to four byte integer two complement representation.</para>
+ <quote>1</quote> will be discarded leaving us with a result of <code
+ language="java">11111111_11111111_11111111_11111110</code> equalling -2
+ with respect to four byte integer two complement representation.</para>
- <para>Why not using float / double in favour of bounded <code language="java"
+ <para>Why not using float / double in favour of bounded <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-A">byte</code>,
<code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>,
@@ -3266,7 +3399,7 @@ System.out.println(Integer.toBinaryString(64200)); // Yields 11111010_11001000
</qandaset>
<qandaset defaultlabel="qanda" xml:id="qandaNarrowing137toByte">
- <title>Get a <code language="java">byte</code> from 137</title>
+ <title>Get a <code language="java">byte</code> from 139</title>
<qandadiv>
<qandaentry>
@@ -3284,13 +3417,14 @@ System.out.println(b);</programlisting>
<answer>
<para>A four byte <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
- representation of 139 reads
- <code language="java">00000000_00000000_00000000_10001011</code>. The cast <code language="java">b
- = (byte) i</code> will strip the leading three bytes leaving
- <code language="java">b</code> containing <code language="java">10001011</code>.</para>
+ representation of 139 reads <code
+ language="java">00000000_00000000_00000000_10001011</code>. The
+ cast <code language="java">b = (byte) i</code> will strip the
+ leading three bytes leaving us with <code language="java">b</code>
+ containing <code language="java">10001011</code>.</para>
<para>Since byte values in <xref linkend="glo_Java"/> are being
- represented as signed values using two-complement notation this
+ represented as signed values in two-complement notation this
equals decimal -117.</para>
</answer>
</qandaentry>
@@ -3310,9 +3444,10 @@ System.out.println(b);</programlisting>
mimic a code portion in <xref linkend="glo_Java"/> showing the
catastrophic error.</para>
- <para>Start with a <code language="java">double</code> variable using a value
- being suitable to be assigned to a <code language="java">short</code> variable
- using a cast (narrowing).</para>
+ <para>Start with a <code language="java">double</code> variable
+ using a value being suitable to be assigned to a <code
+ language="java">short</code> variable using a cast
+ (narrowing).</para>
<para>Then in a second step raise this value breaking your short
variable's upper limit.</para>
@@ -3329,9 +3464,9 @@ System.out.println(value);</programlisting>
<para>Execution yields an expected integer output of
<computeroutput>2331</computeroutput>. However increasing our
- <code language="java">level</code> variable's value from 2331.12 to 42331.12
- yields an output of <computeroutput>-23205</computeroutput> due to
- an overflow.</para>
+ <code language="java">level</code> variable's value from 2331.12
+ to 42331.12 yields an output of
+ <computeroutput>-23205</computeroutput> due to an overflow.</para>
</answer>
</qandaentry>
</qandadiv>
@@ -3352,7 +3487,8 @@ System.out.println(value);</programlisting>
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
values to <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
- values. This requires scaling down <quote>half</quote> the <code language="java"
+ values. This requires scaling down <quote>half</quote> the <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
data type's range <inlineequation>
<m:math display="inline">
@@ -3660,7 +3796,8 @@ System.out.println(value);</programlisting>
<m:mi>32</m:mi>
</m:msup>
</m:math>
- </inlineequation> seems to be equal to <code language="java">2 * (<link
+ </inlineequation> seems to be equal to <code language="java">2 *
+ (<link
xlink:href="https://docs.oracle.com/javase/9/docs/api/constant-values.html#java.lang.Integer.MAX_VALUE">Integer.MAX_VALUE</link>
+ 1))</code> (why?) Joe's first attempt reads:</para>
@@ -3785,8 +3922,9 @@ Process finished with exit code 1</screen>
</m:math>
</inlineequation> (truncating). This indeed yields the desired
result for non-negative values. So why does Joe encounter a
- division by zero runtime exception when executing <code language="java">longValue
- / (2 * (Integer.MAX_VALUE + 1))</code>?</para>
+ division by zero runtime exception when executing <code
+ language="java">longValue / (2 * (Integer.MAX_VALUE +
+ 1))</code>?</para>
<para>Unfortunately Joe's implementation is seriously flawed for
even two reasons:</para>
@@ -3794,13 +3932,14 @@ Process finished with exit code 1</screen>
<orderedlist>
<listitem>
<para>The constant <code language="java"
- xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html">Integer</code>.<code language="java"
+ xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html">Integer</code>.<code
+ language="java"
xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#MAX_VALUE">MAX_VALUE</code>
already suggests we will not be able to increase its value
while staying as an <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>.
- The expression <code language="java">Integer.MAX_VALUE + 1</code> will be
- evaluated using <code language="java"
+ The expression <code language="java">Integer.MAX_VALUE +
+ 1</code> will be evaluated using <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
rather than <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
@@ -3813,11 +3952,12 @@ _____________________________________
<para>This is the binary representation of the unintended
result <code language="java"
- xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html">Integer</code>.<code language="java"
+ xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html">Integer</code>.<code
+ language="java"
xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#MIN_VALUE">MIN_VALUE</code>
- due to an arithmetic overflow. The expression <code language="java">2 *
- (Integer.MAX_VALUE + 1)</code> then gives rise to a second
- overflow error:</para>
+ due to an arithmetic overflow. The expression <code
+ language="java">2 * (Integer.MAX_VALUE + 1)</code> then gives
+ rise to a second overflow error:</para>
<programlisting language="java"> 10000000_00000000_00000000_00000000
+ 10000000_00000000_00000000_00000000
@@ -3826,20 +3966,22 @@ _____________________________________
</listitem>
</orderedlist>
- <para>Both errors combined surprisingly result in a value of
- <code language="java">0</code> explaining the <quote>division by zero</quote>
- error message. There are two possible solutions:</para>
+ <para>Both errors combined surprisingly result in a value of <code
+ language="java">0</code> explaining the <quote>division by
+ zero</quote> error message. There are two possible
+ solutions:</para>
<glosslist>
<glossentry>
- <glossterm><code language="java">(int) (longValue / (2L * (Integer.MAX_VALUE +
- 1L)))</code></glossterm>
+ <glossterm><code language="java">(int) (longValue / (2L *
+ (Integer.MAX_VALUE + 1L)))</code></glossterm>
<glossdef>
- <para>Introducing <code language="java">2L</code> or <code language="java">1L</code> (one is
- sufficient) in favour of simply using 2 and 1 turns both
- addition and multiplication into operations involving at
- least one <code language="java">long</code> argument. Thus for both
+ <para>Introducing <code language="java">2L</code> or <code
+ language="java">1L</code> (one is sufficient) in favour of
+ simply using 2 and 1 turns both addition and multiplication
+ into operations involving at least one <code
+ language="java">long</code> argument. Thus for both
operations the <xref linkend="glo_Java"/> runtime will use
<code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
@@ -3858,23 +4000,25 @@ _____________________________________
</glossentry>
<glossentry>
- <glossterm><code language="java">(int) (longValue / 2 / (Integer.MAX_VALUE +
- 1L))</code></glossterm>
+ <glossterm><code language="java">(int) (longValue / 2 /
+ (Integer.MAX_VALUE + 1L))</code></glossterm>
<glossdef>
<para>Same result as before.</para>
<note>
- <para>This time the expression starts with <code language="java">longValue
- / 2 ...</code> Since the variable <code language="java">longValue</code>
- is of type <code language="java"
- xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
- the expression <code language="java">longValue / 2</code> will be
- evaluated by the <xref linkend="glo_Java"/> runtime using
+ <para>This time the expression starts with <code
+ language="java">longValue / 2 ...</code> Since the
+ variable <code language="java">longValue</code> is of type
<code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
+ the expression <code language="java">longValue / 2</code>
+ will be evaluated by the <xref linkend="glo_Java"/>
+ runtime using <code language="java"
+ xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
arithmetics. The result will subsequently be divided by
- <code language="java">Integer.MAX_VALUE + 1L</code> again using <code language="java"
+ <code language="java">Integer.MAX_VALUE + 1L</code> again
+ using <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
arithmetic.</para>
</note>
@@ -3934,8 +4078,9 @@ short sum = a + 7; <co linkends="sd1_co_expressionTypeIntToShort-2"
<callout arearefs="sd1_co_expressionTypeIntToShort-2-co"
xml:id="sd1_co_expressionTypeIntToShort-2">
- <para>Declaring a short variable <code language="java">sum</code> assigning 4
- + 7.This yields a compile time error:</para>
+ <para>Declaring a short variable <code
+ language="java">sum</code> assigning 4 + 7.This yields a
+ compile time error:</para>
<screen>Type mismatch: cannot convert from int to short</screen>
</callout>
@@ -3950,8 +4095,8 @@ short sum = a + 7; <co linkends="sd1_co_expressionTypeIntToShort-2"
</question>
<answer>
- <para>The expression <code language="java">a + 7</code> contains a variable
- <quote>a</quote> of type <code language="java"
+ <para>The expression <code language="java">a + 7</code> contains a
+ variable <quote>a</quote> of type <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
to the plus operator's left and an <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
@@ -3959,19 +4104,21 @@ short sum = a + 7; <co linkends="sd1_co_expressionTypeIntToShort-2"
yields an <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
result (the <quote>biggest</quote> type of both operands) which
- cannot be assigned to the variable <code language="java">sum</code> of type <code language="java"
+ cannot be assigned to the variable <code
+ language="java">sum</code> of type <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>.</para>
<para>The very same argument seems to apply for the expression
- <code language="java">4 + 7</code> even better: This time the plus operator acts
- on two <code language="java"
+ <code language="java">4 + 7</code> even better: This time the plus
+ operator acts on two <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
operands. However the <xref linkend="glo_Java"/> compiler is
<quote>clever</quote> enough casting the <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
result 11 to the <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-B">short</code>
- variable <code language="java">sum</code> without any loss of information.</para>
+ variable <code language="java">sum</code> without any loss of
+ information.</para>
</answer>
</qandaentry>
</qandadiv>
@@ -3988,7 +4135,8 @@ short sum = a + 7; <co linkends="sd1_co_expressionTypeIntToShort-2"
<programlisting language="java">System.out.println(8 / 9);</programlisting>
<para>The output is <computeroutput>0</computeroutput> rather than
- <code language="java">0.888888...</code> . Explain this result.</para>
+ <code language="java">0.888888...</code> . Explain this
+ result.</para>
</question>
<answer>
@@ -3999,9 +4147,10 @@ short sum = a + 7; <co linkends="sd1_co_expressionTypeIntToShort-2"
<para>According to <uri
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.3-300-A-2">https://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.3-300-A-2</uri>
- the floating point value <code language="java">0.88888...</code> will be
- <quote>rounded toward zero</quote> yielding an int value of
- <code language="java">0</code> rather than <code language="java">1</code>.</para>
+ the floating point value <code language="java">0.88888...</code>
+ will be <quote>rounded toward zero</quote> yielding an int value
+ of <code language="java">0</code> rather than <code
+ language="java">1</code>.</para>
</answer>
</qandaentry>
</qandadiv>
@@ -4054,9 +4203,9 @@ System.out.println("value=" + a);
a = a + 1; // Error: Type mismatch: cannot convert from int to byte
System.out.println("New value=" + a);</programlisting>
- <para>What do you learn about the two operators
- <quote><code language="java">+</code></quote> an
- <quote><code language="java">a++</code></quote>? Explain this error's
+ <para>What do you learn about the two operators <quote><code
+ language="java">+</code></quote> an <quote><code
+ language="java">a++</code></quote>? Explain this error's
cause.</para>
</listitem>
</orderedlist>
@@ -4107,7 +4256,8 @@ System.out.println("New value=" + a);</programlisting>
<listitem>
<para>The compile time error is due to the definition of the
- <quote>+</quote> operator in Java always returning an <code language="java"
+ <quote>+</quote> operator in Java always returning an <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
rather than a byte. Consider:</para>
@@ -4119,8 +4269,8 @@ System.out.println(a + b);</programlisting>
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
value.</para>
- <para>If the expression <code language="java">a + b</code> was of data type
- <code language="java"
+ <para>If the expression <code language="java">a + b</code> was
+ of data type <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-A">byte</code>
in <xref linkend="glo_Java"/> an arithmetic overflow as in the
subsequent code example would occur:</para>
@@ -4132,14 +4282,15 @@ byte sum = (byte) (a + b);
System.out.println(sum);</programlisting>
<para>The explicit type conversion (a so called <quote>type
- cast</quote> or cast for short) forces the 4-byte
- <code language="java">int</code> into a one-byte variable <code language="java">sum</code>
- thereby loosing its original value and returning -126
- instead.</para>
-
- <para>Conclusion: <code language="java">a = a + 1</code> and <code language="java">a++</code>
- (surprisingly) differ in behaviour when being applied to
- non-<code language="java">int</code> variables.</para>
+ cast</quote> or cast for short) forces the 4-byte <code
+ language="java">int</code> into a one-byte variable <code
+ language="java">sum</code> thereby loosing its original value
+ and returning -126 instead.</para>
+
+ <para>Conclusion: <code language="java">a = a + 1</code> and
+ <code language="java">a++</code> (surprisingly) differ in
+ behaviour when being applied to non-<code
+ language="java">int</code> variables.</para>
</listitem>
</orderedlist>
</answer>
@@ -4168,13 +4319,15 @@ System.out.println(2147483647 + 1L);</programlisting>
</question>
<answer>
- <para>The value 2147483647 is actually the largest possible <code language="java"
+ <para>The value 2147483647 is actually the largest possible <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
value <classname
xlink:href="https://docs.oracle.com/javase/9/docs/api/java/lang/Integer.html">Integer</classname>.<property
xlink:href="https://docs.oracle.com/javase/9/docs/api/java/lang/Integer.html#MAX_VALUE">MAX_VALUE</property>.
- The plus operator in the first expression <code language="java">2147483647 +
- 1</code> acts on two operands of type <code language="java"
+ The plus operator in the first expression <code
+ language="java">2147483647 + 1</code> acts on two operands of type
+ <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>.
Thus the resulting sum will be of type <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
@@ -4199,12 +4352,14 @@ System.out.println(2147483647 + 1L);</programlisting>
xlink:href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.3-220">http://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.3-220</uri>
for details.</para>
- <para>On contrary the plus operator in the expression
- <code language="java">2147483647 + 1L</code> acts on an <code language="java"
+ <para>On contrary the plus operator in the expression <code
+ language="java">2147483647 + 1L</code> acts on an <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-C">int</code>
to its left and a <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>
- to its right. The result will thus be of type <code language="java"
+ to its right. The result will thus be of type <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.1-100-D">long</code>:</para>
<screen> 01111111_11111111_11111111_11111111 2147483647
@@ -4249,18 +4404,19 @@ System.out.println(2147483647 + 1L);</programlisting>
</question>
<answer>
- <para>The expression <code language="java">x == y</code> evaluates to
- <code language="java">false</code>. This surprising result is due to limited
- precision regarding both <code language="java"
+ <para>The expression <code language="java">x == y</code> evaluates
+ to <code language="java">false</code>. This surprising result is
+ due to limited precision regarding both <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">float</code>
and <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">double</code>
IEEE representations: A given value will be approximated as close
as possible.</para>
- <para>Adding <code language="java">System.out.println(x - y)</code> yields a value
- of -1.1102230246251565E-16 denoting the representational deviation
- of <code language="java">x</code> and <code language="java">y</code>.</para>
+ <para>Adding <code language="java">System.out.println(x -
+ y)</code> yields a value of -1.1102230246251565E-16 denoting the
+ representational deviation of <code language="java">x</code> and
+ <code language="java">y</code>.</para>
<para>Comparing <code language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.2.3-100">float</code>
@@ -4512,8 +4668,8 @@ System.out.println("Difference: " + difference);</programlisting><screen>Differe
</m:mrow>
</m:math>
</inlineequation>. Complete the following code to calculate the
- result and write it to standard output using
- <code language="java">System.out.println(...)</code>:</para>
+ result and write it to standard output using <code
+ language="java">System.out.println(...)</code>:</para>
<programlisting language="java">public static void main(String[] args) {
@@ -4552,9 +4708,9 @@ System.out.println("Difference: " + difference);</programlisting><screen>Differe
<glossdef>
<para>Instead of immediately using the expression as an
- argument to <code language="java">System.out.println(...)</code> we may
- assign its value to a variable prior to output
- creation:</para>
+ argument to <code
+ language="java">System.out.println(...)</code> we may assign
+ its value to a variable prior to output creation:</para>
<programlisting language="java">public static void main(String[] args) {
@@ -4629,11 +4785,13 @@ System.out.println("A circle of radius " + radius + " will cover an area of " +
</question>
<answer>
- <para>The solution is straightforward. We add the <code language="java"
+ <para>The solution is straightforward. We add the <code
+ language="java"
xlink:href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.12.4">final</code>
- modifier to the definition of our variable <code language="java">pi</code>. In
- addition we use capital letters <code language="java">PI</code> reflecting the
- naming convention for constants:</para>
+ modifier to the definition of our variable <code
+ language="java">pi</code>. In addition we use capital letters
+ <code language="java">PI</code> reflecting the naming convention
+ for constants:</para>
<programlisting language="java" linenumbering="numbered">final double PI = 3.141592653589793;
double radius = 2.3; // Computing a circle's area
@@ -4953,7 +5111,8 @@ char c = 'A'; // ASCII 65
System.out.println(s + c);</programlisting>
<para>Execution results in <computeroutput>66</computeroutput>.
- What is the <code language="java">s+c</code> expression's type?</para>
+ What is the <code language="java">s+c</code> expression's
+ type?</para>
<tip>
<para>Try to assign the expression to another variable and
@@ -4963,9 +5122,10 @@ System.out.println(s + c);</programlisting>
</question>
<answer>
- <para>Both <code language="java">short</code> and <code language="java">char</code> require two
- bytes in <xref linkend="glo_Java"/>. It is thus surprising that a
- mixed expression has got neither of both input types:</para>
+ <para>Both <code language="java">short</code> and <code
+ language="java">char</code> require two bytes in <xref
+ linkend="glo_Java"/>. It is thus surprising that a mixed
+ expression has got neither of both input types:</para>
<programlisting language="java">short s = 1;
char c = 'A';
@@ -4973,8 +5133,9 @@ short resultShort = s + c; // Incompatible types Required: short found: int
char resultChar= s + c; // Incompatible types Required: char found: int</programlisting>
<para>According to the compiler's error message the expression
- <code language="java">s + c</code> is of type <code language="java">int</code>. Why choosing a
- result type being twice the size of both input types?</para>
+ <code language="java">s + c</code> is of type <code
+ language="java">int</code>. Why choosing a result type being twice
+ the size of both input types?</para>
<para>The two input types have different ranges:</para>
@@ -5037,8 +5198,8 @@ char resultChar= s + c; // Incompatible types Required: char found: int</prog
</glossentry>
</glosslist>
- <para>A promotion to <code language="java">int</code> guarantees correct results
- in all circumstances.</para>
+ <para>A promotion to <code language="java">int</code> guarantees
+ correct results in all circumstances.</para>
</answer>
</qandaentry>
</qandadiv>
@@ -5105,32 +5266,34 @@ System.out.println("e=" + e);</programlisting>
(possibly) start wailing about your success rate.</para>
<tip>
- <para>Both <code language="java">x++</code> (postfix notation) and
- <code language="java">++x</code> (infix notation) are expressions themselves
- which might even be rewritten as <code language="java">(x++)</code> and
- <code language="java">(++x)</code> for the sake of clarity. The difference is
- not about operator precedence rules but simply about the values
- of these expressions when being assigned to other
- variables.</para>
+ <para>Both <code language="java">x++</code> (postfix notation)
+ and <code language="java">++x</code> (infix notation) are
+ expressions themselves which might even be rewritten as <code
+ language="java">(x++)</code> and <code
+ language="java">(++x)</code> for the sake of clarity. The
+ difference is not about operator precedence rules but simply
+ about the values of these expressions when being assigned to
+ other variables.</para>
</tip>
</question>
<answer>
<para>As inferred by the hint the biggest problem is about
- understanding postfix and infix notation of the operators
- <code language="java">++</code> and <code language="java">--</code>. A corresponding expression
- evaluates to:</para>
+ understanding postfix and infix notation of the operators <code
+ language="java">++</code> and <code language="java">--</code>. A
+ corresponding expression evaluates to:</para>
<itemizedlist>
<listitem>
- <para><code language="java">a = x++</code> yields a ==x: The value of x
- <emphasis role="bold">before</emphasis> incrementing
- it.</para>
+ <para><code language="java">a = x++</code> yields a ==x: The
+ value of x <emphasis role="bold">before</emphasis>
+ incrementing it.</para>
</listitem>
<listitem>
- <para><code language="java">a = ++x</code> yields a ==(x + 1): The value of x
- <emphasis role="bold">after</emphasis> incrementing it.</para>
+ <para><code language="java">a = ++x</code> yields a ==(x + 1):
+ The value of x <emphasis role="bold">after</emphasis>
+ incrementing it.</para>
</listitem>
</itemizedlist>
@@ -5182,9 +5345,9 @@ System.out.println("a = " + a + ", b = " + b + ", c = " + c);</programlisting>
<screen>a = 7, b = 7, c = 1</screen>
<para>Decompose this cryptic assignment into a series of multiple
- elementary ones like e.g. <code language="java">a++</code> by possibly introducing
- one or more helper variables. Thus your code shall become longer
- but better to understand.</para>
+ elementary ones like e.g. <code language="java">a++</code> by
+ possibly introducing one or more helper variables. Thus your code
+ shall become longer but better to understand.</para>
<tip>
<para>Read about evaluation of expressions and <link
@@ -5218,17 +5381,19 @@ System.out.println("a = " + a + ", b = " + b + ", c = " + c);</programlisting>
<listitem>
<para><code language="java">++b % c--</code></para>
- <para>This one deserves further attention: The <code language="java">%</code>
- operator will act on <code language="java">b</code>'s value <emphasis
+ <para>This one deserves further attention: The <code
+ language="java">%</code> operator will act on <code
+ language="java">b</code>'s value <emphasis
role="bold">after</emphasis> incrementing (infix notation) and
- <code language="java">c</code>'s value <emphasis role="bold">before</emphasis>
- decrementing (postfix notation).</para>
+ <code language="java">c</code>'s value <emphasis
+ role="bold">before</emphasis> decrementing (postfix
+ notation).</para>
</listitem>
</orderedlist>
- <para>We introduce a helper variable <code language="java">sum</code> for
- decomposing our code into the above described four
- subexpressions:</para>
+ <para>We introduce a helper variable <code
+ language="java">sum</code> for decomposing our code into the above
+ described four subexpressions:</para>
<programlisting language="java">int a = 3, b = 6, c = 2;