i think u are asking about c++ ?
be more specific. when asking questions.

The integer data type can only represent whole numbers but they are stored exactly in all circumstances. Integers are often used to count discrete objects such as elements of an array, characters in a string, or iterations of a loop.

The range of numbers covered by the integer type is system-dependent. The majority of computers use 32 bits for their integer arithmetic (1 bit for the sign and 31 for the magnitude) giving a number range of -2,147,483,648 to +2,147,483,647.
Some systems have an even larger integer range but a few very small systems only allow 16-bit integer arithmetic so that their integer range is only -32,768, to +32,767.

anyways..
see the links below too.