Jul 09
Data types specify the size and type of values that can be stored.
Data types are categorised as :
- Primitive types (also called intrinsic or built-in types)
- Non-Primitive types ( also called derived types)
Primitive types
|
Data Type |
Group | Size(in bits) | Default Value | Range | Example |
| byte | Integer | 8 | 0 | -128 to 127 | 10 , 24 |
| short | 16 | 0 | -32768 to 32767 | 500 , 786 | |
| int | 32 | 0 | -2147483648 to 2147483647 | 89,945 , 37865 | |
| long | 64 | 0 | -9223372036854775808 to 9223372036854775807 | 78L , -650L | |
| float | Floating point numbers | 32 | 0.0 | -1.4e-45 to 3.4e+38 | 78.5f , -68.0f |
| double | 64 | 0.0 | -4.9e-324 to 1.7e+308 | 56.25 , 5. , .67 | |
| char | Characters | 16 | \u0000 | \u0000 to \uFFFF | ‘r’ , ‘>’ , ‘=’ |
| boolean | Boolean | 1 bit used in 32 bit integer | false | not applicable | true or false |
Non-Primitive types
- It includes types which are composed of primitive types.
- Reference types,arrays,enum,interfaces all come under this category.
- The default value of reference types is null.
An important non-primitive type provided by Java language is String.
Here, String is a class used to hold set of characters within double quotes.
String objects are immutable, means once initialized their values cannot be altered.
Use of String type
String str=” Java is platform independent ” ;
since it is immutable, the content of str cannot be changed.
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