Constants in C programming language, as the name suggests are the data that doesn't change. Constants are also known as literals. There are five types of constants or literals available in C programming language as shown below.
- Integer Constants
- Floating-point Constants
- Character Constants
- String Constants
- Enumeration Constants
Integer Constants/Literals
Integer constants, as the name suggests, are integer values ie; numbers like 1, 20 etc. In C programming language, we can have integer constants of 3 different bases (or radix) namedDecimal (Base 10), Hexadecimal (Base 16) or Octal (base 8). During the declaration of an integer constant, a prefix is used along with the value to specify the base or radix.
- For decimal literals, no prefix is used.
- Prefix used for hexadecimal:
0x / 0X - Prefix used for octal:
0
Examples of different integer constants
123 /* decimal constant*/ 0x9b /* hexadecimal constant*/ 0X9c /* hexadecimal constant*/ 0456 /* octal constant*/
In C programming, you can use upper case or lower case letters (
ABCDEF or abcdef) as part of hexadecimal literals.