diff --git a/Doc/Sd1/arrays.xml b/Doc/Sd1/arrays.xml
index 692508c2eafd7721fd166adc04277d12ccf17652..5f77350d179fdbf82cacb13c5569ff9230a2768a 100644
--- a/Doc/Sd1/arrays.xml
+++ b/Doc/Sd1/arrays.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Arrays</title>
<section xml:id="sw1SectionArrays">
<title/>
diff --git a/Doc/Sd1/class.xml b/Doc/Sd1/class.xml
deleted file mode 100644
index 96e7f86d7823d17a79153c2ed6b217e006080649..0000000000000000000000000000000000000000
--- a/Doc/Sd1/class.xml
+++ /dev/null
@@ -1,215 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<chapter version="5.0" xml:id="sd1ClassesInstancesState"
- xmlns="http://docbook.org/ns/docbook"
- xmlns:xlink="http://www.w3.org/1999/xlink"
- xmlns:xi="http://www.w3.org/2001/XInclude"
- xmlns:svg="http://www.w3.org/2000/svg"
- xmlns:m="http://www.w3.org/1998/Math/MathML"
- xmlns:html="http://www.w3.org/1999/xhtml"
- xmlns:db="http://docbook.org/ns/docbook">
- <title>-------------------------------- Classes, instances and internal
- state (20.10)</title>
-
- <section xml:id="sd1VariableExercises">
- <title>Extending our interest calculator</title>
-
- <qandaset defaultlabel="qanda" xml:id="sd1QandaExtendInterest">
- <qandadiv>
- <qandaentry>
- <question>
- <para>Our current <code>Account</code> class does not handle
- negative balances accordingly. Typically banks will charge a
- different interest rate whenever an account is in debt i.e. having
- a negative balance. In this case a second so called default
- interest rate (being significantly higher) will be applied.</para>
-
- <para>Extend the current project by adding a new instance variable
- <varname>defaultInterestRate</varname> along with getter and
- setter methods. Then change the implementation of
- <code>applyInterest()</code> and <code>applyInterest(int
- years)</code> by using the correct interest value according to the
- account's balance being positive or negative.</para>
-
- <caution>
- <para>Do not forget to change the <command>Javadoc</command>
- comments accordingly!</para>
- </caution>
- </question>
-
- <answer>
- <annotation role="make">
- <para role="eclipse">Sd1/interest/V2</para>
- </annotation>
-
- <para>We introduce a new variable <code>defaultInterestRate</code>
- to cover negative balance values:</para>
-
- <programlisting language="java"> private static double
- interestRate = 1.5, // applied to positive balances
- <emphasis role="bold">defaultInterestRate = 15.; // applied to negative balances</emphasis></programlisting>
-
- <para>We need the appropriate getter and setter methods in
- <classname
- xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html">Account</classname>:</para>
-
- <programlisting language="java"> /**
- * @return
- * the current default interest rate value.
- */
- public static double <link
- xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html#getDefaultInterestRate--">getDefaultInterestRate()</link> {
- return defaultInterestRate;
- }
-
- /**
- * This interest rate will be applied to negative balances. In contrast
- * {{@link #setInterestRate(double)} will handle positive balance values.
- *
- * @param defaultInterestRate
- * the desired default interest rate value.
- */
- public static void <link
- xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html#setDefaultInterestRate-double-">setDefaultInterestRate(double defaultInterestRate)</link> {
- Account.defaultInterestRate = defaultInterestRate;
- }</programlisting>
-
- <para>The computed interest depends on positive or negative
- balance values:</para>
-
- <programlisting language="java"> public void applyInterest(int years) {
- if (0 < balance) {
- balance = balance * Math.pow((1 + interestRate / 100), years) ;
- } else if (balance < 0){
- balance = balance * Math.pow((1 + defaultInterestRate / 100), years) ;
- }
- }</programlisting>
-
- <para>A complete solution including updated
- <productname>Javadoc</productname> comments can be downloaded
- <link
- xlink:href="https://cloud.mi.hdm-stuttgart.de/owncloud/public.php?service=files&t=577bc9091391524692b6d812a6d2737a">from
- here</link>.</para>
- </answer>
- </qandaentry>
- </qandadiv>
- </qandaset>
-
- <qandaset defaultlabel="qanda" xml:id="sd1VariableComplexExpression">
- <title>Programmers favourite expression</title>
-
- <qandadiv>
- <qandaentry>
- <question>
- <para>Consider the following code fragment:</para>
-
- <programlisting language="java"> int a = 6,
- b = 7,
- c = -3,
- result = 0;
-
- result += ++a - b++ + --c;</programlisting>
-
- <para>Rewrite this code by decomposing the last line into several
- lines to make the code easier to understand.</para>
-
- <para>Hint: After execution of your modified code all variable
- must have identical values with respect to the original code. In
- other words: Your modifications shall not alter the code's
- behaviour in any way.</para>
- </question>
-
- <answer>
- <para>Incrementing <code>++a</code> and decrementing
- <code>--c</code> happens prior to adding / subtracting their
- values to the variable <code>result</code> (prefix notation). The
- increment operation <code>b--</code> in contrast happens after
- being being subtracted from variable <code>result</code> (postfix
- notation). The following code snippet is thus equivalent:</para>
-
- <programlisting language="java"> int a = 6,
- b = 7,
- c = -3,
- result = 0;
- ++a;
- --c;
- result += a - b + c; // or even: result = result + a - b + c;
- b++;</programlisting>
- </answer>
- </qandaentry>
- </qandadiv>
- </qandaset>
-
- <qandaset defaultlabel="qanda" xml:id="sd1QandaIntOverflow">
- <title>Integer value considerations.</title>
-
- <qandadiv>
- <qandaentry>
- <question>
- <para>Consider the following piece of code:</para>
-
- <programlisting language="java">int a = ..., b = ...;
-...// statements being omitted
-int sum = a + b;</programlisting>
-
- <para>Which representation related problem may arise here? May you
- supply a solution?</para>
- </question>
-
- <answer>
- <para>The sum of a and b may either exceed
- <code>java.lang.Integer.MAX_VALUE</code> or in turn may be less
- than <code>java.lang.Integer.MIN_VALUE</code>. To avoid this type
- of overflow error our variable <code>sum</code> may be declared of
- type long:</para>
-
- <programlisting language="java">int a = ..., b = ...;
-...// statements being omitted
-long sum = a + b;</programlisting>
-
- <para>Unfortunately this does not (yet) help at all: Since both
- operands <code>a</code> and <code>b</code> are of type
- <code>int</code> the expression <code>a + b</code> is also of type
- int and will be evaluated as such. To circumvent this problem we
- have to cast at least one operand to type <code>long</code> prior
- to computing the sum. This works since the cast operator
- <code>(long)</code> does have higher priority than the
- <quote>+</quote> operator</para>
-
- <programlisting language="java">int a = ..., b = ...;
-...// statements being omitted
-long sum = (long)a + b;</programlisting>
- </answer>
- </qandaentry>
- </qandadiv>
- </qandaset>
-
- <qandaset defaultlabel="qanda" xml:id="sde1QandaFraction">
- <title>A class representing fractions</title>
-
- <qandadiv>
- <qandaentry>
- <question>
- <para>Implement a class representing fractions. You may find a
- dummy implementation containing some (not yet working) sample
- usage code being contained in a <code>main()</code> method. This
- Maven archive also includes a <xref linkend="glo_Junit"/>
- test.</para>
-
- <annotation role="make">
- <para role="eclipse">Sd1/fraction/V05</para>
- </annotation>
- </question>
-
- <answer>
- <annotation role="make">
- <para role="eclipse">Sd1/fraction/V1</para>
- </annotation>
-
- <para>See implementation at <link
- xlink:href="Ref/api/P/fraction/V1/de/hdm_stuttgart/mi/sd1/fraction/Fraction.html">Fraction</link>.</para>
- </answer>
- </qandaentry>
- </qandadiv>
- </qandaset>
- </section>
-</chapter>
diff --git a/Doc/Sd1/coreClasses.xml b/Doc/Sd1/coreClasses.xml
index aa7f46e0393b60518459cb41d77520102ab86420..fe85c3bab44567b80e13bb789928a4fb23931197 100644
--- a/Doc/Sd1/coreClasses.xml
+++ b/Doc/Sd1/coreClasses.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Core Classes</title>
<section xml:id="sw1SectionCoreClasses">
<title/>
diff --git a/Doc/Sd1/errorHandling.xml b/Doc/Sd1/errorHandling.xml
index 565be73157eb0caa27d054c0712bdbe37c93b029..765765eaf54447772c64d26dc047b0d6f1dd7d00 100644
--- a/Doc/Sd1/errorHandling.xml
+++ b/Doc/Sd1/errorHandling.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Error Handling</title>
<section xml:id="sw1SectionErrorHandling">
<title/>
diff --git a/Doc/Sd1/inheritance.xml b/Doc/Sd1/inheritance.xml
index bb1b5aa731f814cfc88ff40c6b7079d4b8d56c99..b505d67daf2aace0feb1854af908e99e29c997d9 100644
--- a/Doc/Sd1/inheritance.xml
+++ b/Doc/Sd1/inheritance.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Inheritance</title>
<section xml:id="sw1SectionInheritance">
<title/>
diff --git a/Doc/Sd1/interfacesAbstractClasses.xml b/Doc/Sd1/interfacesAbstractClasses.xml
index d3e40dbde2d2805255265f94c45a77319634079e..c5f64de79f7f60ad1d05812d5d06a418f79cc2d6 100644
--- a/Doc/Sd1/interfacesAbstractClasses.xml
+++ b/Doc/Sd1/interfacesAbstractClasses.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Interfaces and Abstract Classes</title>
<section xml:id="sw1SectionInterfacesAbstractClasses">
<title/>
diff --git a/Doc/Sd1/objectsClasses.xml b/Doc/Sd1/objectsClasses.xml
index 8c5414605a2e8371b466ed5b217c53de2e8ceeeb..cb6ff0408ee65c5f570579e243ce9249bc0fc740 100644
--- a/Doc/Sd1/objectsClasses.xml
+++ b/Doc/Sd1/objectsClasses.xml
@@ -7,11 +7,959 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Objects and Classes</title>
- <section xml:id="sw1SectionObjectsClasses">
- <title/>
+ <section xml:id="sd1CrabsEnhancePrepare">
+ <title>Preparations</title>
- <para/>
+ <itemizedlist>
+ <listitem>
+ <para>Read ...</para>
+
+ <itemizedlist>
+ <listitem>
+ <para>static vs. non-static methods and fields.</para>
+ </listitem>
+
+ <listitem>
+ <para>the <code>final</code> keyword's meaning.</para>
+ </listitem>
+
+ <listitem>
+ <para>The way a garbage collector works.</para>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+ </itemizedlist>
+ </section>
+
+ <section xml:id="sd1GeometryClasses">
+ <title>Dealing with geometry classes</title>
+
+ <qandaset defaultlabel="qanda" xml:id="sd1ImplementRectangle">
+ <title>Modeling rectangles</title>
+
+ <qandaentry>
+ <question>
+ <para>We want to model rectangles being defined y width and height
+ to allow for the subsequently demonstrated operations:</para>
+
+ <programlisting language="java">final Rectangle r = new Rectangle(8, 5); <co
+ linkends="sw1CalloutRectangle-1" xml:id="constructor"/>
+
+System.out.println("Perimeter:" + r.getPerimeter()<co
+ linkends="sw1CalloutRectangle-2" xml:id="getPerimeter"/>);
+System.out.println("Area:" + r.getArea()<co linkends="sw1CalloutRectangle-3"
+ xml:id="getArea"/>);
+
+r.setWidth(4); <co linkends="sw1CalloutRectangle-4" xml:id="setWidth"/>
+r.setHeight(7);
+
+System.out.println("Perimeter:" + r.getPerimeter()); <co
+ linkends="sw1CalloutRectangle-5"
+ xml:id="sw1CalloutRectangle-5-co"/>
+System.out.println("Area:" + r.getArea());</programlisting>
+
+ <calloutlist>
+ <callout arearefs="constructor" xml:id="sw1CalloutRectangle-1">
+ <para>Creating an instance of class
+ <classname>Rectangle</classname> by calling a non-default
+ constructor which allows for providing width (8) and height
+ (5).</para>
+ </callout>
+
+ <callout arearefs="getPerimeter" xml:id="sw1CalloutRectangle-2">
+ <para>Returning the rectangle's perimeter, </para>
+ </callout>
+
+ <callout arearefs="getArea" xml:id="sw1CalloutRectangle-3">
+ <para>Returning the rectangle's area.</para>
+ </callout>
+
+ <callout arearefs="setWidth" xml:id="sw1CalloutRectangle-4">
+ <para>Setting with and height to new values.</para>
+ </callout>
+
+ <callout arearefs="sw1CalloutRectangle-5-co"
+ xml:id="sw1CalloutRectangle-5">
+ <para>Write (possibly) changed perimeter and area values.</para>
+ </callout>
+ </calloutlist>
+
+ <para>You may start from the following
+ <classname>Rectangle</classname> class dummy implementation:</para>
+
+ <programlisting language="java">/**
+ * Representing rectangular shapes.
+ *
+ */
+public class Rectangle {
+
+ /**
+ *
+ * @param width The rectangle's width
+ * @param heigth The rectangle's height
+ */
+ public Rectangle (double width, double heigth) {
+ //TODO
+ }
+ /**
+ * @return The rectangle's area.
+ */
+ public double getArea() {
+ return 0; // TODO
+ }
+
+ /**
+ * @return The rectangle's perimeter.
+ */
+ public double getPerimeter() {
+ return 0; // TODO
+ }
+
+ /**
+ * @return The rectangle's width.
+ */
+ public double getWidth() {
+ return 0; // TODO
+ }
+ /**
+ * @param width The rectangle's new width
+ */
+ public void setWidth(double width) {
+ // TODO
+ }
+
+ /**
+ * @return The rectangle's height.
+ */
+ public double getHeight() {
+ return 0; // TODO
+ }
+
+ /**
+ * @param width The rectangle's new height
+ */
+ public void setHeight(double height) {
+ // TODO
+ }
+}</programlisting>
+ </question>
+
+ <answer>
+ <para>First we define two instance (= non-static) variables
+ <code>width</code> and <code>height</code> representing a
+ <classname>Rectangle</classname>'s corresponding two parameters
+ <code>width</code> and <code>height</code>:</para>
+
+ <programlisting language="java">public class Rectangle {
+
+ // Instance variables representing a rectangle's parameters
+ private double <emphasis role="bold">width</emphasis>, <emphasis role="bold">height</emphasis>;
+...
+}</programlisting>
+
+ <para>Next we allow for changing these two parameters:</para>
+
+ <programlisting language="java">public class Rectangle {
+
+ // Instance variables representing a rectangle's parameters
+ private double width, height;
+
+...
+ /**
+ * @param width Changing the rectangle's width
+ */
+ public void setWidth(double w) {
+ <emphasis role="bold">width = w;</emphasis>
+ }
+
+ /**
+ * @param width Changing the rectangle's height
+ */
+ public void setHeight(double height) {
+ <emphasis role="bold">this.height = height;</emphasis>
+ }
+...
+}</programlisting>
+
+ <para>Note the subtle implementation difference between
+ <methodname>setWidth(...)</methodname> and
+ <methodname>setHeight(...)</methodname>:</para>
+
+ <glosslist>
+ <glossentry xml:id="glossMethodDiff1">
+ <glossterm><methodname>setWidth(double
+ w)</methodname></glossterm>
+
+ <glossdef>
+ <para>We use the formal parameter name <quote>w</quote>. Its
+ name does not conflict with the instance variable name
+ <quote>width</quote> being defined at class level. We can
+ simply assign this value to our corresponding instance
+ variable using <code>width = w;</code>.</para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry xml:id="xmlMethodDiff2">
+ <glossterm><methodname>setHeight(double
+ height)</methodname></glossterm>
+
+ <glossdef>
+ <para>The method's formal parameter <quote>height</quote>
+ shadows the instance variable's name being defined at class
+ level. We need the <quote>this</quote> keyword in
+ <code>this.height = height</code> to resolve the
+ ambiguity.</para>
+ </glossdef>
+ </glossentry>
+ </glosslist>
+
+ <para>Both ways are perfectly legal. The complete implementation
+ including all remaining methods reads:</para>
+
+ <programlisting language="java">/**
+ * Representing rectangular shapes.
+ *
+ */
+public class Rectangle {
+
+ // Instance variables representing a rectangle's parameters
+ private double width, height;
+
+ /**
+ *
+ * @param width The rectangle's width
+ * @param heigth The rectangle's height
+ */
+ public Rectangle (double width, double height) {
+ setWidth(width);
+ setHeight(height);
+ }
+ /**
+ * @return The rectangle's area.
+ */
+ public double getArea() {
+ return width * height;
+ }
+
+ /**
+ * @return The rectangle's perimeter.
+ */
+ public double getPerimeter() {
+ return 2 * (width + height);
+ }
+
+ /**
+ * @return The rectangle's width.
+ */
+ public double getWidth() {
+ return width;
+ }
+ /**
+ * @param width The rectangle's new width
+ */
+ public void setWidth(double w) {
+ width = w;
+ }
+
+ /**
+ * @return The rectangle's height.
+ */
+ public double getHeight() {
+ return height;
+ }
+
+ /**
+ * @param width The rectangle's new height
+ */
+ public void setHeight(double height) {
+ this.height = height;
+ }
+}</programlisting>
+ </answer>
+ </qandaentry>
+ </qandaset>
+
+ <qandaset defaultlabel="qanda" xml:id="qandasetGeometry">
+ <title>Modeling circles</title>
+
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>We provide a corresponding class
+ <classname>Circle</classname> dummy implementation:</para>
+
+ <programlisting language="java">package step1.dummy;
+
+/**
+ * A circle of given radius
+ *
+ */
+public class Circle {
+
+ /**
+ * A new circle
+ *
+ * @param radius
+ * The desired radius.
+ */
+ public Circle(double radius) {
+ // TODO
+ }
+
+ /**
+ * @return The circle's area.
+ */
+ public double getArea() {
+ return 0; // TODO
+ }
+
+ /**
+ * @return The circle's perimeter.
+ */
+ public double getPerimeter() {
+ return 0; // TODO
+ }
+
+ /**
+ * @return The circle's radius.
+ */
+ public double getRadius() {
+ return 0; // TODO
+ }
+
+ /**
+ * @param radius
+ * Setting the circle's radius to a new value.
+ */
+ public void setRadius(double radius) {
+ // TODO
+ }
+}</programlisting>
+
+ <para>Instances of this class shall be usable in the following
+ fashion:</para>
+
+ <programlisting language="java"> public static void main(String[] args) {
+ final Circle c = new Circle(2.3);
+
+ System.out.println("Radius:" + c.getRadius());
+ System.out.println("Perimeter:" + c.getPerimeter());
+ System.out.println("Area:" + c.getArea());
+
+ // Changing the circle's radius to a different value
+ c.setRadius(4.7);
+
+ System.out.println("Radius:" + c.getRadius());
+ System.out.println("Perimeter:" + c.getPerimeter());
+ System.out.println("Area:" + c.getArea());
+ }</programlisting>
+
+ <para>Hint: Obviously you'll have to define an instance variable
+ within Circle to keep track of its current radius value. All
+ methods mentioned above simply depend on this single value.</para>
+ </question>
+
+ <answer>
+ <para>We define an instance variable <code>radius</code> inside
+ our class <classname>Circle</classname>:</para>
+
+ <programlisting language="java">public class Circle {
+
+ double radius;
+...
+}</programlisting>
+
+ <para>Next we implement our method to change a circle's
+ radius:</para>
+
+ <programlisting language="java"> public void setRadius(double r) {
+ radius = r;
+ }</programlisting>
+
+ <para>Note that we have chosen a different value for the method's
+ formal radius parameter to be <quote>r</quote> rather than
+ <quote>radius</quote>. Many people prefer to use radius here
+ making it easier for a programmer to recognize the expected name
+ in the generated <xref linkend="glo_Javadoc"/>:</para>
+
+ <programlisting language="java"> public void setRadius(double radius) {
+ <emphasis role="bold">this.</emphasis>radius = radius;
+ }</programlisting>
+
+ <para>This requires the usage of the <code>this</code> keyword to
+ distinguish the formal parameter in <methodname>setRadius(double
+ radius)</methodname> from the instance variable previously being
+ defined within our class <classname>Circle</classname>. In other
+ words: We have to resolve a name shadowing conflict.</para>
+
+ <para>The rest of the implementation is (quite) straightforward. A
+ complete class reads:</para>
+
+ <programlisting language="java">package step1;
+
+/**
+ * A circle of given radius
+ *
+ */
+public class Circle {
+
+ double radius;
+
+ /**
+ * A new circle
+ * @param radius The desired radius.
+ */
+ public Circle(double radius) {
+ setRadius(radius);
+ }
+
+ /**
+ * @return The circle's area.
+ */
+ public double getArea() {
+ return radius * radius * Math.PI;
+ }
+
+ /**
+ * @return The circle's perimeter.
+ */
+ public double getPerimeter() {
+ return 2 * Math.PI * radius;
+ }
+
+ /**
+ * @return The circle's radius.
+ */
+ public double getRadius() {
+ return radius;
+ }
+
+ /**
+ * @param radius Setting the circle's radius to a new value.
+ */
+ public void setRadius(double radius) {
+ this.radius = radius;
+ }
+}</programlisting>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question>
+ <para>Our current Circle and Rectangle class only models shape
+ parameters and does not allow for translation in a coordinate
+ system:</para>
+
+ <itemizedlist>
+ <listitem>
+ <para>Add two more instance variables x and y and
+ corresponding setter methods to account for a shape's
+ translation vector with respect to the origin (0,0). The
+ following hint may be helpful:</para>
+
+ <programlisting language="java"> /**
+ * @param x The circle's x center coordinate value
+ */
+ public void setX(double x) {
+ // TODO
+ }
+ /**
+ * @param x The circle's x center coordinate value
+ */
+ public void setY(double y) {
+ // TODO
+ }</programlisting>
+ </listitem>
+
+ <listitem>
+ <para>We would like Rectangle and Circle instances to be
+ visualized as <acronym>SVG</acronym> graphics. Add a method
+ <methodname>void writeSvg()</methodname> to both classes which
+ allows for <acronym>SVG</acronym> code export to standard
+ output. You may want to read the w3schools <link
+ xlink:href="http://www.w3schools.com/svg/svg_rect.asp">rectangle</link>
+ and <link
+ xlink:href="http://www.w3schools.com/svg/svg_circle.asp">circle</link>
+ examples. Use System.out.println(...) calls to create the
+ desired <acronym>SVG</acronym> output. You may need
+ <code>\"</code> to represent double quotes as in the
+ subsequent example:</para>
+
+ <programlisting language="java">System.out.println("<rect width=\"20\"" ...</programlisting>
+ </listitem>
+ </itemizedlist>
+
+ <para>The following code snippet may serve to illustrate the
+ intended use of <methodname>void writeSvg()</methodname>:</para>
+
+ <programlisting language="java">public class Driver {
+
+ public static void main(String[] args) {
+
+ System.out.println("<!DOCTYPE html><html><body>");
+ System.out.println(" <svg width='300' height='200' >");
+
+ // Draw a rectangle as SVG
+ final Rectangle r = new Rectangle(5, 4);
+ r.setX(2);
+ r.setY(1);
+ r.writeSvg();
+
+ // Draw a circle as SVG
+ final Circle c = new Circle(1, 1, 3);
+ c.setX(3);
+ c.setY(1);
+ c.writeSvg();
+ System.out.println(" </svg >");
+ System.out.println("</body></html>");
+ }
+}</programlisting>
+
+ <para>Implement the method <methodname>void
+ writeSvg()</methodname> in both classes
+ <classname>Rectangle</classname> and
+ <classname>Circle</classname>. This should produce an output
+ result like:</para>
+
+ <programlisting language="java"><!DOCTYPE html>
+<html>
+ <body>
+ <svg width='300' height='200' >
+ <emphasis role="bold"><rect width='100.0' height='80.0' x='40.0' y='20.0'' style='fill:rgb(0,255,0);stroke-width:3;stroke:rgb(0,0,0)'/></emphasis>
+ <emphasis role="bold"><circle r='60.0' cx='60.0' cy='20.0' style='fill:rgb(0,0,255);stroke-width:3;stroke:rgb(0,0,0)'/></emphasis>
+ </svg >
+ </body>
+</html></programlisting>
+
+ <para>You may enter this output into a file sfg.html. A web
+ browser should visualize this output as:</para>
+
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="Ref/Fig/svgGeometry.png"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ </question>
+
+ <answer>
+ <programlisting language="java"> private double x, y, width, height;
+ ...
+ /**
+ * @param x The rectangle's x center coordinate value
+ */
+ public void setX(double x) {
+ this.x = x;
+ }
+ /**
+ * @param x The rectangle's x center coordinate value
+ */
+ public void setY(double y) {
+ this.y = y;
+ }
+
+public void writeSvg() {
+ final int scale = 20;
+ System.out.println(
+ "<rect width='" + scale * width +"' height='" + scale * height +
+ "' x='" + scale * x + "'" + " y='" + scale * y + "'" +
+ "' style='fill:rgb(0,255,0);stroke-width:3;stroke:rgb(0,0,0)'/>");
+ }
+}</programlisting>
+
+ <programlisting language="java">public class Circle {
+
+ double x, y, radius;
+...
+
+ /**
+ * @param x The circle's x center coordinate value
+ */
+ public void setX(double x) {
+ this.x = x;
+ }
+ /**
+ * @param x The circle's x center coordinate value
+ */
+ public void setY(double y) {
+ this.y = y;
+ }
+
+public void writeSvg() {
+ final int scale = 20;
+
+ System.out.println(
+ "<circle r='" + scale * radius +
+ "' cx='" + scale * x + "'" + " cy='" + scale * y +
+ "' style='fill:rgb(0,0,255);stroke-width:3;stroke:rgb(0,0,0)'/>");
+
+ }
+}</programlisting>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
+ </section>
+
+ <section version="5.0" xml:id="sd1InterestCalculator">
+ <title>Lecture 5 - A simple interest calculator</title>
+
+ <para>Consider the following implementation of an interest
+ calculator:</para>
+
+ <annotation role="make">
+ <para role="eclipse">Sd1/interest/V1</para>
+ </annotation>
+
+ <glosslist>
+ <glossentry>
+ <glossterm>Instance versus class variables and methods</glossterm>
+
+ <glossdef>
+ <para>Examples:</para>
+
+ <glosslist>
+ <glossentry>
+ <glossterm>Instance variables and methods, non-static
+ declaration</glossterm>
+
+ <glossdef>
+ <para><code>private double balance</code>, <code>public void
+ setBalance(double balance)</code></para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry>
+ <glossterm>Class variables and methods, static
+ declaration</glossterm>
+
+ <glossdef>
+ <para><code>private static double </code>interestRate,
+ <code>public static void setInterestRate(double
+ z)</code></para>
+ </glossdef>
+ </glossentry>
+ </glosslist>
+
+ <para>For both categories chapter 5, <quote>Fields in a Class
+ Definition</quote> and <quote>Methods in a Class
+ Definition</quote>.</para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry>
+ <glossterm>Formal parameter names and variable scopes</glossterm>
+
+ <glossdef>
+ <programlisting language="java"> /**
+ * Setting the interest rate common to all accounts.
+ *
+ * @param z
+ * the desired (global) interest rate.
+ */
+ public static void setInterestRate(double z) { // Scope of variable "z" limited is just the next block {...},
+ interestRate = z; // in contrast interestRate has class scope.
+ }</programlisting>
+
+ <para>The formal variable's name <quote><code>z</code></quote> may
+ be <emphasis>consistently</emphasis> renamed to any other legal,
+ non-conflicting value like
+ <quote><code>myFunnyVariableName</code></quote>:</para>
+
+ <programlisting language="java"> public static void setInterestRate(double myFunnyVariableName) {
+ interestRate = myFunnyVariableName;
+ }</programlisting>
+
+ <para>Name shadowing conflicts can be resolved by using the keyword
+ <emphasis><code>this</code></emphasis> <coref
+ linkend="sd1ListingThis"/>:</para>
+
+ <programlisting language="java">public class Konto {
+...
+ private double balance; <emphasis role="bold">// variable "stand" being shadowed inside body of setStand(...)</emphasis>
+...
+ public void setStand(double stand) {
+ if (balance <= 10000) {
+ <emphasis role="bold">this</emphasis>.balance <co
+ xml:id="sd1ListingThis"/> = balance; // "this" required to resolve name shadowing conflict
+ // by formal parameter name "double balance".
+ } else {
+ System.out.println("Balance" + balance + " exceeds " + 10000);
+ }
+ }
+...
+}</programlisting>
+ </glossdef>
+ </glossentry>
+
+ <glossentry>
+ <glossterm>Access restrictions public / private / protected to
+ attributes and methods</glossterm>
+
+ <glossdef>
+ <programlisting language="java">public class Account {
+
+ <emphasis role="bold">private</emphasis> static double // Visible for class methods only
+ interestRate = 1.5;
+...
+ <emphasis role="bold">public</emphasis> void applyInterest() { // Externally visible
+ balance = balance * (1 + interestRate / 100);
+ }
+...</programlisting>
+
+ <para>See , chapter 5, <quote>CONTROLLING ACCESS TO CLASS
+ MEMBERS</quote>.</para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry>
+ <glossterm>Method overloading</glossterm>
+
+ <glossdef>
+ <para>Example:</para>
+
+ <programlisting language="java">public class Account {
+
+ public Account() { // Default Constructor without any parameter
+ setBalance(0);
+ }
+...
+ public Account(double balance) { // <emphasis role="bold">Overloaded</emphasis> non-default constructor creating an account
+ setBalance(balance); // with (possibly) non-zero balance.
+ }
+...
+ public void applyInterest() { // Just one year
+ balance = balance *
+ (1 + interestRate / 100);
+ }
+...
+ public void applyInterest(int years) { // <emphasis role="bold">Overloaded</emphasis> method allowing for different time periods.
+ balance = balance *
+ Math.pow((1 + interestRate / 100), years);
+ }
+...
+}</programlisting>
+
+ <para>See , chapter 5, <quote>METHOD OVERLOADING</quote>.</para>
+ </glossdef>
+ </glossentry>
+
+ <glossentry>
+ <glossterm>Use of standard mathematical functions</glossterm>
+
+ <glossdef>
+ <programlisting language="java">Math.pow((1 + interestRate / 100), years)</programlisting>
+
+ <para>See , chapter 2, <quote>MATHEMATICAL FUNCTIONS AND
+ CONSTANTS</quote>.</para>
+ </glossdef>
+ </glossentry>
+ </glosslist>
+ </section>
+
+ <section xml:id="sd1VariableExercises">
+ <title>Extending our interest calculator</title>
+
+ <qandaset defaultlabel="qanda" xml:id="sd1QandaExtendInterest">
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>Our current <code>Account</code> class does not handle
+ negative balances accordingly. Typically banks will charge a
+ different interest rate whenever an account is in debt i.e. having
+ a negative balance. In this case a second so called default
+ interest rate (being significantly higher) will be applied.</para>
+
+ <para>Extend the current project by adding a new instance variable
+ <varname>defaultInterestRate</varname> along with getter and
+ setter methods. Then change the implementation of
+ <code>applyInterest()</code> and <code>applyInterest(int
+ years)</code> by using the correct interest value according to the
+ account's balance being positive or negative.</para>
+
+ <caution>
+ <para>Do not forget to change the <command>Javadoc</command>
+ comments accordingly!</para>
+ </caution>
+ </question>
+
+ <answer>
+ <annotation role="make">
+ <para role="eclipse">Sd1/interest/V2</para>
+ </annotation>
+
+ <para>We introduce a new variable <code>defaultInterestRate</code>
+ to cover negative balance values:</para>
+
+ <programlisting language="java"> private static double
+ interestRate = 1.5, // applied to positive balances
+ <emphasis role="bold">defaultInterestRate = 15.; // applied to negative balances</emphasis></programlisting>
+
+ <para>We need the appropriate getter and setter methods in
+ <classname
+ xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html">Account</classname>:</para>
+
+ <programlisting language="java"> /**
+ * @return
+ * the current default interest rate value.
+ */
+ public static double <link
+ xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html#getDefaultInterestRate--">getDefaultInterestRate()</link> {
+ return defaultInterestRate;
+ }
+
+ /**
+ * This interest rate will be applied to negative balances. In contrast
+ * {{@link #setInterestRate(double)} will handle positive balance values.
+ *
+ * @param defaultInterestRate
+ * the desired default interest rate value.
+ */
+ public static void <link
+ xlink:href="Ref/api/P/interest/V2/de/hdm_stuttgart/mi/sd1/interest/Account.html#setDefaultInterestRate-double-">setDefaultInterestRate(double defaultInterestRate)</link> {
+ Account.defaultInterestRate = defaultInterestRate;
+ }</programlisting>
+
+ <para>The computed interest depends on positive or negative
+ balance values:</para>
+
+ <programlisting language="java"> public void applyInterest(int years) {
+ if (0 < balance) {
+ balance = balance * Math.pow((1 + interestRate / 100), years) ;
+ } else if (balance < 0){
+ balance = balance * Math.pow((1 + defaultInterestRate / 100), years) ;
+ }
+ }</programlisting>
+
+ <para>A complete solution including updated
+ <productname>Javadoc</productname> comments can be downloaded
+ <link
+ xlink:href="https://cloud.mi.hdm-stuttgart.de/owncloud/public.php?service=files&t=577bc9091391524692b6d812a6d2737a">from
+ here</link>.</para>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
+
+ <qandaset defaultlabel="qanda" xml:id="sd1VariableComplexExpression">
+ <title>Programmers favourite expression</title>
+
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>Consider the following code fragment:</para>
+
+ <programlisting language="java"> int a = 6,
+ b = 7,
+ c = -3,
+ result = 0;
+
+ result += ++a - b++ + --c;</programlisting>
+
+ <para>Rewrite this code by decomposing the last line into several
+ lines to make the code easier to understand.</para>
+
+ <para>Hint: After execution of your modified code all variable
+ must have identical values with respect to the original code. In
+ other words: Your modifications shall not alter the code's
+ behaviour in any way.</para>
+ </question>
+
+ <answer>
+ <para>Incrementing <code>++a</code> and decrementing
+ <code>--c</code> happens prior to adding / subtracting their
+ values to the variable <code>result</code> (prefix notation). The
+ increment operation <code>b--</code> in contrast happens after
+ being being subtracted from variable <code>result</code> (postfix
+ notation). The following code snippet is thus equivalent:</para>
+
+ <programlisting language="java"> int a = 6,
+ b = 7,
+ c = -3,
+ result = 0;
+ ++a;
+ --c;
+ result += a - b + c; // or even: result = result + a - b + c;
+ b++;</programlisting>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
+
+ <qandaset defaultlabel="qanda" xml:id="sd1QandaIntOverflow">
+ <title>Integer value considerations.</title>
+
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>Consider the following piece of code:</para>
+
+ <programlisting language="java">int a = ..., b = ...;
+...// statements being omitted
+int sum = a + b;</programlisting>
+
+ <para>Which representation related problem may arise here? May you
+ supply a solution?</para>
+ </question>
+
+ <answer>
+ <para>The sum of a and b may either exceed
+ <code>java.lang.Integer.MAX_VALUE</code> or in turn may be less
+ than <code>java.lang.Integer.MIN_VALUE</code>. To avoid this type
+ of overflow error our variable <code>sum</code> may be declared of
+ type long:</para>
+
+ <programlisting language="java">int a = ..., b = ...;
+...// statements being omitted
+long sum = a + b;</programlisting>
+
+ <para>Unfortunately this does not (yet) help at all: Since both
+ operands <code>a</code> and <code>b</code> are of type
+ <code>int</code> the expression <code>a + b</code> is also of type
+ int and will be evaluated as such. To circumvent this problem we
+ have to cast at least one operand to type <code>long</code> prior
+ to computing the sum. This works since the cast operator
+ <code>(long)</code> does have higher priority than the
+ <quote>+</quote> operator</para>
+
+ <programlisting language="java">int a = ..., b = ...;
+...// statements being omitted
+long sum = (long)a + b;</programlisting>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
+
+ <qandaset defaultlabel="qanda" xml:id="sde1QandaFraction">
+ <title>A class representing fractions</title>
+
+ <qandadiv>
+ <qandaentry>
+ <question>
+ <para>Implement a class representing fractions. You may find a
+ dummy implementation containing some (not yet working) sample
+ usage code being contained in a <code>main()</code> method. This
+ Maven archive also includes a <xref linkend="glo_Junit"/>
+ test.</para>
+
+ <annotation role="make">
+ <para role="eclipse">Sd1/fraction/V05</para>
+ </annotation>
+ </question>
+
+ <answer>
+ <annotation role="make">
+ <para role="eclipse">Sd1/fraction/V1</para>
+ </annotation>
+
+ <para>See implementation at <link
+ xlink:href="Ref/api/P/fraction/V1/de/hdm_stuttgart/mi/sd1/fraction/Fraction.html">Fraction</link>.</para>
+ </answer>
+ </qandaentry>
+ </qandadiv>
+ </qandaset>
</section>
</chapter>
diff --git a/Doc/Sd1/workingWithNumbers.xml b/Doc/Sd1/workingWithNumbers.xml
index 9c99672ab7d55fe48f7d8768e4fa450dab8cf0d5..548a2d866c06b8413838dd2d7cbedb4b71ddc886 100644
--- a/Doc/Sd1/workingWithNumbers.xml
+++ b/Doc/Sd1/workingWithNumbers.xml
@@ -7,7 +7,7 @@
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:db="http://docbook.org/ns/docbook">
- <title>Statements</title>
+ <title>Working with Numbers</title>
<section xml:id="sw1SectionWorkingWithNumbers">
<title/>
diff --git a/Doc/lectures.xml b/Doc/lectures.xml
index ce1bf3433847b98b75388b1192fd0e8a2cbb3d53..998734ed5d31d15a7051949cbd83fa50940e25d8 100644
--- a/Doc/lectures.xml
+++ b/Doc/lectures.xml
@@ -34,15 +34,21 @@
<xi:include href="Sd1/languageFundamentals.xml" xpointer="element(/1)"/>
<xi:include href="Sd1/statements.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/objectsClasses.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/coreClasses.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/arrays.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/inheritance.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/errorHandling.xml" xpointer="element(/1)"/>
+
<xi:include href="Sd1/workingWithNumbers.xml" xpointer="element(/1)"/>
- <xi:include href="Sd1/interfacesAbstractClasses.xml" xpointer="element(/1)"/>
- <xi:include href="Sd1/class.xml" xpointer="element(/1)"/>
+ <xi:include href="Sd1/interfacesAbstractClasses.xml"
+ xpointer="element(/1)"/>
<xi:include href="Sd1/loop.xml" xpointer="element(/1)"/>
diff --git a/ws/eclipse/Sde1/Figur/src/step1/DriverCircle.java b/ws/eclipse/Sde1/Figur/src/step1/DriverCircle.java
index 0cfc4b56e5db6e48b500e9f256101952eb233e75..d9c48f26b0cb5192420ea21efae27bca002f0bc6 100644
--- a/ws/eclipse/Sde1/Figur/src/step1/DriverCircle.java
+++ b/ws/eclipse/Sde1/Figur/src/step1/DriverCircle.java
@@ -3,13 +3,15 @@ package step1;
public class DriverCircle {
public static void main(String[] args) {
- Circle c = new Circle(2.3);
+ final Circle c = new Circle(2.3);
+
System.out.println("Radius:" + c.getRadius());
System.out.println("Perimeter:" + c.getPerimeter());
System.out.println("Area:" + c.getArea());
// Changing the circle's radius to a different value
c.setRadius(4.7);
+
System.out.println("Radius:" + c.getRadius());
System.out.println("Perimeter:" + c.getPerimeter());
System.out.println("Area:" + c.getArea());
diff --git a/ws/eclipse/Sde1/Figur/src/step1/DriverRctangle.java b/ws/eclipse/Sde1/Figur/src/step1/DriverRectangle.java
similarity index 80%
rename from ws/eclipse/Sde1/Figur/src/step1/DriverRctangle.java
rename to ws/eclipse/Sde1/Figur/src/step1/DriverRectangle.java
index aa66f1e308d02de92a2a09663adfed83e4c81087..0aa0b888b4d6493e022dab641558a60091ab95f9 100644
--- a/ws/eclipse/Sde1/Figur/src/step1/DriverRctangle.java
+++ b/ws/eclipse/Sde1/Figur/src/step1/DriverRectangle.java
@@ -1,16 +1,18 @@
package step1;
-public class DriverRctangle {
+public class DriverRectangle {
public static void main(String[] args) {
- Rectangle r = new Rectangle(8, 5);
+ final Rectangle r = new Rectangle(8, 5);
+
System.out.println("Perimeter:" + r.getPerimeter());
System.out.println("Area:" + r.getArea());
r.setWidth(4);
r.setHeight(7);
+
System.out.println("Perimeter:" + r.getPerimeter());
System.out.println("Area:" + r.getArea());
diff --git a/ws/eclipse/Sde1/Figur/src/step1/Rectangle.java b/ws/eclipse/Sde1/Figur/src/step1/Rectangle.java
index 4db06de036fb01b803242ec0f759eef88afbe487..ec621bbf6c43d53430722321171518134ccbaf43 100644
--- a/ws/eclipse/Sde1/Figur/src/step1/Rectangle.java
+++ b/ws/eclipse/Sde1/Figur/src/step1/Rectangle.java
@@ -58,4 +58,4 @@ public class Rectangle {
public void setHeight(double height) {
this.height = height;
}
-}
+}
\ No newline at end of file