600.107 Intro to Programming in Java

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600.107 Intro to Programming in Java

• Jai Madhok
• Teaching Assistant
• 5th July 2007

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Todays Agenda

• Miscellaneous Details (finals, operators, etc)
• Using built in Java classes and their functions
• Math Class
• Character Class
• File Input/Output
• Example filesDemo.java
• College Pro Painters- Guided Lab exercize

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The final

• Usage- for named constants- reserve word
• Examples
• conversion rates for currency
• measurement units for cooking
• length-weight conversions, etc
• Why use them?
• What are the advantages?
• Good programming practice to use them wherever
  appropraite.

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Assignment Combinations

• , - , , /
• Useful- make code simpler to understand
• Looks cleaner
• Can help save a lot of typing in programs where
  arithmetic operations are used a lot
• Some examples

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Commonly used escape sequences

• Can be used to format output on screen or onto
  files, etc
• \t leaves a tab space
• \ quotation mark
• \n takes the cursor to the next line
• \\ if you want to print a backslash
• Few more in the text, these are the main ones
• Use them whenever you feel the need to

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The String Class its methods

• char charAt(int index)
• int indexOf(char ch)
• String concat(String str)
• int length()
• String substring()- 2 types
• String toUpperCase()
• String toLowerCase()
• Concatenation with

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Math Class

• Math.ceil()
• Math.floor()
• Math.pow()
• Others in the text and in the documentation

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Files

• Why use files?
• Reading data from a formatted file
• Writing output onto a file