Variables

A variable is an identifier which is used to represent a single data item that is a numeric quantity or a character constant. The data item have to be assigned to the variable at a few point of time in the program. This data item could then be accessed later in the program commonly by referring to the variable name. Unlike constants which remain unchanged in during the execution of a program, a variable might take various values at various times.

All variables must be declared before they are used in the program. The common form of a declaration is displays as: -

Data-type var_list;

Data types have to be a valid data type and var_list might consist of one or more identifier names along with comma operators. The statement tells the compiler what the variable names are and what category of data they contain. A few declarations are: -

int count;

short int num;

double balance;

float amount;

The words int, short int, double and float is keywords and cannot be used as variable names.