Constants in C

The Constants in C language refers to fixed values that do not change during the execution of the program.

Constants in C

The constants in C programming are of two types:

  • Numeric Constants
  • Character Constants

Numeric Constants

All integer and real number constants are called numeric constants.

Integer Constants

Numeric constants without a floating point is called integer constant. There are three type of integer constants.

  • Decimal integer constant
  • Octal integer constant
  • Hexa-decimal integer constant

Examples: 123, -321, 0, 654321, +89

Real Number Constants

The numeric constants with floating point are called real constants.

Examples: 0.00567, 0.85, 400.567, -0.87, .78

Character Constants

A single character or a sequence of characters enclosed within quotes is called character constant. There are two types of character constants:

  • Single character constant
  • String constant

Single Character Constant

A single character enclosed within a pair of single quotes is called single character constant.

Examples: ‘2’ , ‘b’ , ‘:’

String Constants

A sequence of characters are enclosed within a pair of double quotes is called string constant.

Examples: “Hello CSAdeeb” , “120+5” , “a” , “how..?”

Declaring a Variable as Constant

A variable in C language can be declared as constant using the keyword const at the time initialization.


const int maximum_mark = 100;