Introduction to Java Part 3

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Introduction to Java Part 3

• Informatik III

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Comments
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Comments in Java

• / This kind of comment can span multiple lines
  /
• // This kind is to the end of the line
• / This kind of comment is a special
  javadoc style comment /
• Source code should be documented via comments

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Parameter of methods
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Method parameters

• A method can get parameters
• Placeholder for the actual values which are
  passed to the method
• Anther method may call this method and pass the
  real values to the method

public class Math public void
multiplyWrite(int a, int b)
System.out.println(a b)
Math variable1 new Math() variable1.multiplyWri
te(4,2)
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Return values
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Return values

• A method can return the result of its calculation
• void means that no return value is returned
• If a return value is included then the calling
  method can use the return value.

public class Math public int multiply(int
a, int b) return a b
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Return values - Explained
method multiply (int a, int b)
Another method calling multiply
Tell me what is 12 x 14
Ahthe result is 168
Method main calls method multiply
Method multiply returns the result
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Code Example
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Code Example Part 1
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Code Example Part 2

• This is a class which uses the other class

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Exercises

• Make your application more flexible
• Perform the following exercise
• http//www.vogella.de/articles/JavaIntroduction/ar
  ticle.htmlexercise08
• http//www.vogella.de/articles/JavaIntroduction/ar
  ticle.htmlexercise10
• http//www.vogella.de/articles/JavaIntroduction/ar
  ticle.htmlexercise12
• http//www.vogella.de/articles/JavaIntroduction/ar
  ticle.htmlexercise14