Manav Goyal

Data Types - Java

  • If Data Types are not Initialized then by default it will store a Null/Empty value
  • final dataType var = val => Initialize a Constant variable
  • Types
    • Primitive
      • Byte
        • Size = 1 byte
        • Range = -128 to 127
        • byte var = 12
      • Short
        • Size = 2 byte
        • short var = 123
      • Integer
        • Size = 4 byte
        • int var = 1234
      • Long
        • Size = 8 byte
        • long var = 123456L
      • Float
        • Size = 4 byte
        • Can store Decimal values
        • float var = 123.45F
      • Double
        • Size = 8 byte
      • Character
        • Size = 1 byte
        • Can store Characters
        • char var = '@'
      • Boolean
        • Size = 1 byte
        • true/false
        • boolean var = true
    • Java
    • Non-Primitive
      • String
        • String var = "val"
      • Array
      • Class
  • Wrapper Class => Provided by java.lang
    • Integer
    • Short
  • Collections
    • List
    • Set
    • Map
    • Properties
  • Casting
    • Implicit
      • Casting a Data Type with bigger size/container into a Data Type with smaller size
      • Java does it automatically
    • Explicit
      • Data may get lost
      • (dataType)val
      • Integer.parseInt(val) => Convert into Integer
      • Float.parseFloat(val)
      • Double.parseDouble(val)
      • Long.parseLong(val)
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