Comma Operator

The comma operator is used to evaluate more than one expression in a single statement. Expressions are written separated by commas and the expressions are evaluated from left to right. The right most result is result is result of  compound expression.

 Consider  a = ( b = 1, c = 2, b+c );

  here value of a is 3.

Parentheses are necessary because comma operator has a lower precedence than assignment operator.

Example :

#include <stdio.h>

void main( )

{

int a, b, prod ;

prod = ( a = 5 , b = 4 , a * b ) ;

printf("Product = %d", prod);

}