Java ISU Variables

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Java ISU - Variables

• By Christina Lee
• And Andrew James

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Variables

• an item of data named by an identifier
• must explicitly provide a name that begins with a
  letter and a type for each variable
• a variable declaration type name
• The variable's scope determined implicitly by
  the location of the variable declaration

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Data Type

• determines the values that the variable can
  contain and the operations that can be performed
  on it
• contains a single value of the appropriate size
  and format for its type a number, a character,
  or a boolean value.

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Data Type
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Assignment Operators

• performs a function on one, two, or three
  operands
• allow you to perform an arithmetic, shift, or
  bitwise operation and an assignment operation all
  with one operator.

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Assignment Operators
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Example - MaxVariablesDemo

• public class MaxVariablesDemo
• public static void main(String args)  
  
• // integers
• byte largestByte Byte.MAX_VALUE
• short largestShort Short.MAX_VALUE
• int largestInteger Integer.MAX_VALUE
• long largestLong Long.MAX_VALUE 
• // real numbers
• float largestFloat Float.MAX_VALUE
• double largestDouble Double.MAX_VALUE 
  
• // other primitive types
• char aChar 'S'
• boolean aBoolean true

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Example - MaxVariablesDemo

• // display them all
• System.out.println("The largest byte value is "
  largestByte) System.out.println("The
  largest short value is " largestShort)
  System.out.println("The largest integer value is
  " largestInteger) System.out.println("T
  he largest long value is " largestLong) 
  
• System.out.println("The largest float value is
  " largestFloat) System.out.println("The
  largest double value is " largestDouble) 
  
• if (Character.isUpperCase(aChar))
• System.out.println("The character " aChar "
  is upper case.")
• else
• System.out.println("The character "
  aChar " is lower case.")
• System.out.println("The value of aBoolean is "
  aBoolean)

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Output of the program

• The largest byte value is 127
• The largest short value is 32767
• The largest integer value is 2147483647
• The largest long value is 9223372036854775807
• The largest float value is 3.40282e38
• The largest double value is 1.79769e308
• The character S is upper case.
• The value of aBoolean is true

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The End

• Thank you for your listening )