Identifiers and Keyword in C

  

Identifier:

An Identifier is the symbolic name given to an entity such as variable, data type, function, array etc. It must be unique. It is a plain sequence of alphabet or digits which compulsorily start with an alphabet. It do not allow to use punctuations, blank space or sign. There is no length limit of an identifier but you need to specify it to compiler in advance.

Ex: valid identifier : area,volume,tax,h42,sum,etc.

     invalid identifier: area of circle,x+y,3ab,etc

 

Keyword:

Keyword are the word whose meaning has already been explained to the compiler. The keyword can not be use as variable word because assigning a new meaning to the keyword is not allowed by the C compiler. The keyword are also called as Reserved word.

There are only 32 keyword in C language. They are as follow: