Variables And Keywords

Variables And Keywords

It is a data name which is used to store data and may change during program execution. It is opposite to constant. Variable name is a name given to memory cells location of a computer where data is stored.

* Rules for varibales:

• First character should be letter or alphabet.
• Keywords are not allowed to use as a variable name.
• White space is not allowed.
• C is case sensitive i.e. UPPER and lower case are significant.
• Only underscore, special symbol is allowed between two characters.
• The length of indentifier may be upto 31 characters but only only the first 8 characters are significant by compiler.
• (Note: Some compilers allow variable names whose length may be upto 247 characters. But, it is recommended to use maximum 31 characters in variable name. Large variable name leads to occur errors.)

Keywords :

Keywords are the system defined identifiers.
All keywords have fixed meanings that do not change.
White spaces are not allowed in keywords.
Keyword may not be used as an indentifier.
It is strongly recommended that keywords should be in lower case letters.
There are totally 32(Thirty Two) keywords used in a C programming.