Keywords Identifiers and Constant

 Keywords

 Keywords are those words whose meaning have been fixed & is known, To its compiler, we can not change the meaning of keywords, it we try to do so an error massage will generates. So, we can say that keywords are the reserve words.

  Example: - int, float, double etc.

Identifiers: -

 Identifiers are used for naming program element that is variables, symbolic constant and arrays.

These are defined by the user.

Constant: -

 Data items that do not change their values while the program execute, are called constant.

1-Nummeric Constant

  a) Integer

  b) Float or Real

2-Character Constant

  a) Character Constant (Single)

  b) String Constant (Double)