Variable

Variable.

1.Variable is an entity that change during program execution. Example when we write r = 45 i.e. x can hold different value at different times so r is a variable.
2.A variable may be integer,character,float,double etc.

 * Rules for constructing Variable Names :

1.A variable name must be start with alphabet or underscore.
2.A variable name is any combination of 1 to 31 alphabets,digits or underscores.
3.No commas,special symbol(rather than underscore [ _ ] ) or blanks are allowed within a variable name
4.Example of valid variable names : ram, _ram, d_x, _voids, echo_,