Primitive Data Types in Java

Data types are the foundation of a programming language. There are 8 types of primitive in java: boolean, byte, char, double, float, int, long and short. 

• The boolean data type holds value either true or false. The default value of the boolean is false. 

•  The char data type represents a single character 'a', 'B', 'c'. It's 16-bit integer number(un-signed). Un-signed means non-negetive.

 The others are numeric data types in java (char is included as its number type). They are the following:
        

Integer Numbers:

•  byte: 1 byte (8 bit) : Stores hole numbers from -128 to 127 
•  char: 2 bytes (16 bit) : Stores hole numbers from 0 to 65535 
•  short: 2 bytes (16 bit) : Stores hole numbers from -32768 to 32767
•  int: 4 bytes (32 bit) : Stores hole numbers from -2147483648 to 2147483647 
• long: 8 bytes (64 bit) : Stores hole numbers from -9223372036854775808 to 9223372036854775807  

Floating-point numbers:  

1.  float: 4 bytes (32 bit): Store fractional numbers. Sufficient for storing 6 to 7 decimal digits.
2.  double: 8 bytes (64 bit): Store fractional numbers. Sufficient for storing 15 decimal digits.