diff --git a/Doc/Sd1/Ref/Statements/onlineBanking.png b/Doc/Sd1/Ref/Statements/onlineBanking.png
new file mode 100644
index 0000000000000000000000000000000000000000..b99c307d3c2b7e92184653aae98db8ac9c1eb735
Binary files /dev/null and b/Doc/Sd1/Ref/Statements/onlineBanking.png differ
diff --git a/Doc/Sd1/objectsClasses.xml b/Doc/Sd1/objectsClasses.xml
index 136125d8b6c75d2cef94171571b96e0c52d6d312..68b3cef053b8028d5cddef635fce37f91dd90c3c 100644
--- a/Doc/Sd1/objectsClasses.xml
+++ b/Doc/Sd1/objectsClasses.xml
@@ -39,13 +39,13 @@
</listitem>
<listitem>
- <para>allow for tailored access to attributes.</para>
+ <para>allow for tailored access to methods and attributes.</para>
</listitem>
</itemizedlist>
</figure>
<figure xml:id="sd1_fig_classRectangle">
- <title>Class describing rectangles</title>
+ <title>A class describing rectangles</title>
<programlisting language="java">public class Rectangle {
int width;
diff --git a/Doc/Sd1/statements.xml b/Doc/Sd1/statements.xml
index 9cf8c01a953a372cc24c5c77cf28bdf8bea1340f..fdb9bb0242797255d156d117f57143d0bfb06169 100644
--- a/Doc/Sd1/statements.xml
+++ b/Doc/Sd1/statements.xml
@@ -166,7 +166,9 @@ if (100000 <= initialAmount) {
// Rich customer, 1,2% interest rate
System.out.println(
"Interest:" + 1.2 * initialAmount / 100);
-} </programlisting><screen>Interest:3840.0</screen></td>
+}
+System.out.println("Done!");</programlisting><screen>Interest:3840.0
+Done!</screen></td>
<td valign="top"><mediaobject>
<imageobject>
@@ -192,7 +194,9 @@ if (100000 <= initialAmount) {
// Joe customer, 0.8% standard interest rate
System.out.println(
"Interest:" + 0.8 * initialAmount / 100);
-}</programlisting><screen>Interest:3.36</screen></td>
+}
+System.out.println("Done!");</programlisting><screen>Interest:3.36
+Done!</screen></td>
<td valign="top"><mediaobject>
<imageobject>
@@ -227,6 +231,20 @@ if (100000 <= initialAmount) {
</informaltable>
</figure>
+ <figure xml:id="sd1_fig_bestPracticeCompareEquals">
+ <title><code>Best practices comparing for equality</code></title>
+
+ <para>Always use</para>
+
+ <programlisting language="java">if (4 == variable) ...</programlisting>
+
+ <para>in favour of:</para>
+
+ <programlisting language="java">if (variable == 4) ...</programlisting>
+
+ <para>See <link xlink:href="sd1_sect_statements_if.html#sd1_note_useLiteralEqualsVariable">detailed explanation</link>.</para>
+ </figure>
+
<qandaset defaultlabel="qanda" xml:id="sd1_qanda_booleanEqual">
<title>Comparing for equality</title>
@@ -304,25 +322,11 @@ int main(int argc, char **args) {
</glossentry>
</glosslist>
- <para>Thus <code>if(count = 4)</code> will always be true irrespective of the variable <code>count</code>'s initial value. Most important: The C compiler will not issue an error or warning unless non-default, more restrictive compile time directive are being activated.</para>
+ <para>Thus <code>if(count = 4)</code> will always be true irrespective of the variable <code>count</code>'s initial value. Most important: The C compiler will not issue an error or warning unless non-default, more restrictive compile time warning options are being activated.</para>
<para>For this reason it is good practice using <code>if (4 == count)</code> instead: Even in C an accidentally mistyped <code>if (4 = count)</code> statement will definitively result in a compile time error most likely saving its author from tedious debugging.</para>
</note>
- <figure xml:id="sd1_fig_bestPracticeCompareEquals">
- <title><code>Best practices comparing for equality</code></title>
-
- <para>Always use</para>
-
- <programlisting language="java">if (4 == variable) ...</programlisting>
-
- <para>in favour of:</para>
-
- <programlisting language="java">if (variable == 4) ...</programlisting>
-
- <para>See <link xlink:href="sd1_sect_statements_if.html#sd1_note_useLiteralEqualsVariable">detailed explanation</link>.</para>
- </figure>
-
<qandaset defaultlabel="qanda" xml:id="sd1_qanda_replaceElseIf">
<title>Replacing <code>if else (...)</code> by introducing a nested <code>if ... else</code></title>
@@ -392,6 +396,16 @@ else
</itemizedlist>
</figure>
+ <figure xml:id="sd1_fig_onlineBanking">
+ <title>Online banking</title>
+
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="Ref/Statements/onlineBanking.png"/>
+ </imageobject>
+ </mediaobject>
+ </figure>
+
<figure xml:id="sd1_fig_ipSpoofing">
<title>IP Spoofing</title>
@@ -413,7 +427,7 @@ else
</figure>
<figure xml:id="sd1_fig_IfOmitBewareIndent">
- <title>The <link xlink:href="https://nakedsecurity.sophos.com/2014/02/24/anatomy-of-a-goto-fail-apples-ssl-bug-explained-plus-an-unofficial-patch/">Apple goto fail SSL bug</link></title>
+ <title>The <link xlink:href="https://nakedsecurity.sophos.com/2014/02/24/anatomy-of-a-goto-fail-apples-ssl-bug-explained-plus-an-unofficial-patch/">Apple <quote><code>goto fail</code></quote> SSL bug</link></title>
<programlisting language="c">static OSStatus
SSLVerifySignedServerKeyExchange(SSLContext *ctx, bool isRsa, SSLBuffer signedParams,
@@ -612,12 +626,16 @@ System.out.println("Failed!");</programlisting>
</figure>
<figure xml:id="sd1_fig_useScannerClass">
- <title>User input by <link xlink:href="https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html">Scanner</link></title>
+ <title>User input recipe</title>
+
+ <programlisting language="java">try (final <link xlink:href="https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html">Scanner</link> scan = new <link xlink:href="https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html">Scanner</link>(<link xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/System.html#in">System.in</link>)){
+ System.out.print("Enter a value:");
+ final int value = scan.<link xlink:href="https://docs.oracle.com/javase/8/docs/api/java/util/Scanner.html#nextInt--">nextInt()</link>;
+ System.out.println("You entered " + value);
+}</programlisting>
- <programlisting language="java">final Scanner scan = new Scanner(System.in);
-System.out.print("Enter a value:");
-final int value = scan.nextInt();
-System.out.println("You entered " + value);</programlisting>
+ <screen>Enter a value:1234567
+You entered 1234567</screen>
<para>See <methodname xlink:href="https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextBoolean()">nextBoolean()</methodname>, <methodname><link xlink:href="https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextByte()">nextByte()</link></methodname> and friends.</para>
</figure>
@@ -945,6 +963,9 @@ switch(number) {
default: System.out.println("Invalid number " + number); break;
}
...</programlisting>
+
+ <screen>Enter a weekday number (1=Monday, 2=Tuesday,...) :>6
+Saturday</screen>
</figure>
<qandaset defaultlabel="qanda" xml:id="sd1_qanda_whyBreak">
@@ -1133,7 +1154,7 @@ switch(day % 7) {
<figure xml:id="sd1_fig_switchOnString">
<title>Switching on strings</title>
- <para>Starting from <xref linkend="glo_Java"/> 7 <code>switch</code> statements using <classname xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/String.html">String</classname> based <code>case</code> labels are allowed:</para>
+ <para><xref linkend="glo_Java"/> 7 introduced <classname xlink:href="https://docs.oracle.com/javase/7/docs/api/java/lang/String.html">String</classname> based <code>case</code> labels:</para>
<programlisting language="java">String month, season;
...
@@ -1404,7 +1425,7 @@ public class LeapYear {
<glossterm>Objective</glossterm>
<glossdef>
- <para>Execute the same code multiple times.</para>
+ <para>Execute the same statement multiple times.</para>
</glossdef>
</glossentry>
@@ -1412,7 +1433,7 @@ public class LeapYear {
<glossterm>Solution</glossterm>
<glossdef>
- <para>Copy / paste the code in question:</para>
+ <para>Copy / paste the statement in question:</para>
<programlisting language="java">System.out.println("Do not copy!");
System.out.println("Do not copy!");
@@ -1449,7 +1470,7 @@ switch(repetitions) {
case 1: System.out.println("Do not copy!");
}</programlisting>
- <para>Problem: Clumsy and limited (five lines of output max.)</para>
+ <para>Problem: Clumsy and limited (predefined maximum).</para>
</figure>
<section xml:id="sd1_sect_while">
@@ -1598,7 +1619,7 @@ Goodbye!</screen>We thus use a <code>do ... while</code> loop entering the loop'
<title>for</title>
<figure xml:id="sd1_fig_forConsider">
- <title>Common usage of <code>while</code></title>
+ <title>Frequent usage of <code>while</code></title>
<programlisting language="java">int i = 1; <co linkends="sd1_callout_whileLoopJustCounting-1" xml:id="sd1_callout_whileLoopJustCounting-1-co"/>
@@ -1627,9 +1648,20 @@ while (i < 5 <co linkends="sd1_callout_whileLoopJustCounting-2" xml:id="sd1_c
<figure xml:id="sd1_fig_for">
<title>Replacing <code>while</code> by <code>for</code></title>
- <programlisting language="java">for (int i = 0 <co linkends="sd1_callout_for-1" xml:id="sd1_callout_for-1-co"/>; i < 5 <co linkends="sd1_callout_for-2" xml:id="sd1_callout_for-2-co"/>; i++ <co linkends="sd1_callout_for-3" xml:id="sd1_callout_for-3-co"/>) {
+ <informaltable border="1">
+ <tr>
+ <td><programlisting language="java">for (int i = 0 <co linkends="sd1_callout_for-1" xml:id="sd1_callout_for-1-co"/>; i < 5 <co linkends="sd1_callout_for-2" xml:id="sd1_callout_for-2-co"/>; i++ <co linkends="sd1_callout_for-3" xml:id="sd1_callout_for-3-co"/>) {
...
-}</programlisting>
+}</programlisting></td>
+
+ <td><programlisting language="java">int i = 1; <coref linkend="sd1_callout_for-1-co"/>
+
+while (i < 5 <coref linkend="sd1_callout_for-2-co"/>) {
+ ...
+ i++; <coref linkend="sd1_callout_for-3-co"/>
+}</programlisting></td>
+ </tr>
+ </informaltable>
<calloutlist>
<callout arearefs="sd1_callout_for-1-co" xml:id="sd1_callout_for-1">
@@ -2710,9 +2742,9 @@ for (int i = 1; i <= limit; i++) {
sum += i;
}
-System.out.println("0 + ... + " + limit + " = " + sum); </programlisting></td>
+System.out.println("1 + ... + " + limit + " = " + sum); </programlisting></td>
- <td><screen>0 + ... + 5 = 15 </screen></td>
+ <td><screen>1 + ... + 5 = 15 </screen></td>
</tr>
</informaltable>
</figure>
@@ -2725,9 +2757,9 @@ System.out.println("0 + ... + " + limit + " = " + sum); </programlisting>
<question>
<para>In <xref linkend="sd1_fig_loopCalculations"/> the resulting output was:</para>
- <screen>0 + ... + 5 = 15</screen>
+ <screen>1 + ... + 5 = 15</screen>
- <para>Modify the code to show <computeroutput>1 + 2 + 3 + 4 + 5 = 15</computeroutput> instead.</para>
+ <para>Modify the code to show all contributing values <computeroutput>1 + 2 + 3 + 4 + 5 = 15</computeroutput> instead.</para>
</question>
<answer>
@@ -2926,22 +2958,24 @@ System.out.println(limit + " = " + sum);</programlisting>
</m:math>
</informalequation>
- <para>Write an application which allows for determining the probabilistic success rates by calculating this coefficient. For the German <quote xml:lang="de">Glücksspirale</quote> a possible output reads:</para>
+ <para>Write an application which allows for determining the probabilistic success rates using this coefficient. For the German <quote xml:lang="de">Glücksspirale</quote> a possible output reads:</para>
<screen>Your chance to win when drawing 6 out of 49 is 1 : 13983816</screen>
+ <para>Store parameters like 6 or 49 in variables to keep your software flexible.</para>
+
<tip>
<orderedlist>
<listitem>
- <para>Store parameters like 6 or 49 in variables to keep your software flexible.</para>
- </listitem>
-
- <listitem>
- <para>Use <code>long</code> variables when appropriate to avoid overflow errors.</para>
+ <para>Why is it a bad idea to <abbrev>e.g.</abbrev> compute <inlineequation>
+ <m:math display="inline">
+ <m:mi>49!</m:mi>
+ </m:math>
+ </inlineequation> directly even when using long variables? Remember <xref linkend="sd1_fig_byteOverflow"/>.</para>
</listitem>
<listitem>
- <para>Even if using variables of type <code>long</code> you will not be able to represent e.g. <quote>90!</quote> due to an arithmetic overflow. This problem can be avoided by simplifying <inlineequation>
+ <para>Arithmetic overflow problems can be avoided by simplifying <inlineequation>
<m:math display="inline">
<m:mfrac>
<m:mrow>
@@ -2979,28 +3013,295 @@ System.out.println(limit + " = " + sum);</programlisting>
</m:mrow>
</m:mfrac>
</m:math>
- </inlineequation> beforehand.</para>
- </listitem>
+ </inlineequation> beforehand. You may want to write down an explicit example like <inlineequation>
+ <m:math display="inline">
+ <m:mrow>
+ <m:mrow>
+ <m:mrow>
+ <m:mo>(</m:mo>
- <listitem>
- <para>The following loop allows for computing a given number's factorial:</para>
+ <m:mrow>
+ <m:mtable>
+ <m:mtr>
+ <m:mtd>
+ <m:mi>8</m:mi>
+ </m:mtd>
+ </m:mtr>
+
+ <m:mtr>
+ <m:mtd>
+ <m:mi>3</m:mi>
+ </m:mtd>
+ </m:mtr>
+ </m:mtable>
+ </m:mrow>
- <programlisting language="java">long factorial = 1;
-for (int i = 2; i <= number; i++) {
- factorial *= i;
-}</programlisting>
+ <m:mo>)</m:mo>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mo>=</m:mo>
+
+ <m:mfrac>
+ <m:mrow>
+ <m:mi>8</m:mi>
+
+ <m:mo>!</m:mo>
+ </m:mrow>
- <para>Use similar loops for calculation.</para>
+ <m:mrow>
+ <m:mrow>
+ <m:mi>3</m:mi>
+
+ <m:mo>!</m:mo>
+ </m:mrow>
+
+ <m:mo>â¢</m:mo>
+
+ <m:mrow>
+ <m:mrow>
+ <m:mo>(</m:mo>
+
+ <m:mrow>
+ <m:mi>8</m:mi>
+
+ <m:mo>-</m:mo>
+
+ <m:mi>3</m:mi>
+ </m:mrow>
+
+ <m:mo>)</m:mo>
+ </m:mrow>
+
+ <m:mo>!</m:mo>
+ </m:mrow>
+ </m:mrow>
+ </m:mfrac>
+ </m:mrow>
+ </m:math>
+ </inlineequation> to learn about cancellation of contributing factors.</para>
</listitem>
</orderedlist>
</tip>
</question>
<answer>
- <para>By simple fraction cancellation we get:</para>
+ <para>Consider the following snippet:</para>
+
+ <programlisting language="java">int product = 1;
+for (int i = 1; i < 50; i++) {
+ product *= i;
+ System.out.println(i + "! == " + product);
+}</programlisting>
+
+ <para>This results in:</para>
+
+ <screen>1! == 1
+2! == 2
+3! == 6
+4! == 24
+5! == 120
+6! == 720
+7! == 5040
+8! == 40320
+9! == 362880
+10! == 3628800
+11! == 39916800
+12! == 479001600
+13! == 1932053504
+...
+49! == 0</screen>
+
+ <para>Only results up to <inlineequation>
+ <m:math display="inline">
+ <m:mi>12!</m:mi>
+ </m:math>
+ </inlineequation> are correct: The next term <inlineequation>
+ <m:math display="inline">
+ <m:mi>13!</m:mi>
+ </m:math>
+ </inlineequation> equals 6227020800 which is ways beyond <code xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/Integer.html#MAX_VALUE">Integer.MAX_VALUE</code> == 2147483647 giving rise to a (silent) arithmetic overflow. But even declaring <code>long product = 1</code> does not help much:</para>
+
+ <screen>1! == 1
+2! == 2
+3! == 6
+4! == 24
+5! == 120
+6! == 720
+7! == 5040
+8! == 40320
+9! == 362880
+10! == 3628800
+11! == 39916800
+12! == 479001600
+13! == 6227020800
+14! == 87178291200
+15! == 1307674368000
+16! == 20922789888000
+17! == 355687428096000
+18! == 6402373705728000
+19! == 121645100408832000
+20! == 2432902008176640000
+21! == -4249290049419214848
+...
+49! == 8789267254022766592</screen>
+
+ <para>This time <code>20! == 2432902008176640000</code> is the last correct value being smaller than <code xlink:href="https://docs.oracle.com/javase/8/docs/api/java/lang/Long.html#MAX_VALUE">Long.MAX_VALUE</code> == 9223372036854775807.</para>
+
+ <para>Fortunately we have another option. Consider an example:</para>
+
+ <informalequation>
+ <m:math display="block">
+ <m:mrow>
+ <m:mrow>
+ <m:mrow>
+ <m:mo>(</m:mo>
+
+ <m:mrow>
+ <m:mtable>
+ <m:mtr>
+ <m:mtd>
+ <m:mi>8</m:mi>
+ </m:mtd>
+ </m:mtr>
+
+ <m:mtr>
+ <m:mtd>
+ <m:mi>3</m:mi>
+ </m:mtd>
+ </m:mtr>
+ </m:mtable>
+ </m:mrow>
+
+ <m:mo>)</m:mo>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mo>=</m:mo>
+
+ <m:mfrac>
+ <m:mrow>
+ <m:mrow>
+ <m:mi>8</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>7</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>6</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>5</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>4</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>3</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>2</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>1</m:mi>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mrow>
+ <m:mrow>
+ <m:mo>(</m:mo>
+
+ <m:mi>3</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>2</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>1</m:mi>
+
+ <m:mo>)</m:mo>
+ </m:mrow>
+
+ <m:mo>×</m:mo>
+
+ <m:mrow>
+ <m:mo>(</m:mo>
+
+ <m:mi>5</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>4</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>3</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>2</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>1</m:mi>
+
+ <m:mo>)</m:mo>
+ </m:mrow>
+ </m:mrow>
+ </m:mfrac>
+
+ <m:mo>=</m:mo>
+
+ <m:mfrac>
+ <m:mrow>
+ <m:mrow>
+ <m:mi>8</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>7</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>6</m:mi>
+ </m:mrow>
+ </m:mrow>
+
+ <m:mrow>
+ <m:mrow>
+ <m:mi>3</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>2</m:mi>
+
+ <m:mo>×</m:mo>
+
+ <m:mi>1</m:mi>
+ </m:mrow>
+ </m:mrow>
+ </m:mfrac>
+
+ <m:mo>=</m:mo>
+
+ <m:mi>56</m:mi>
+ </m:mrow>
+ </m:math>
+ </informalequation>
+
+ <para>We generalize this fraction cancellation example:</para>
<equation xml:id="sd1EqnBinomialCalculate">
- <title>Calculating binomials in a slightly more efficient manner rather than just computing three factorials.</title>
+ <title>Calculating binomials by cancelling common factors.</title>
<m:math display="block">
<m:mrow>
@@ -3229,7 +3530,7 @@ for (int i = 2; i <= number; i++) {
</m:math>
</equation>
- <para>As an example we have:</para>
+ <para>And thus:</para>
<informalequation>
<m:math display="block">
@@ -3321,7 +3622,7 @@ for (int i = 2; i <= number; i++) {
</m:math>
</informalequation>
- <para>Calculating numerator and denominator in two separate loops a possible implementation reads:</para>
+ <para>We thus calculate numerator and denominator in two separate loops:</para>
<programlisting language="java">public class Lottery {