Nested While Statements in C

There are several situations where more than one parameter need to be varied over a range of values to obtain the desired results. For example, there may be a function having two variables, say x and y and it is desired to evaluate the function for different values of x and y. In such cases, for every value of x the values of y are varied over the range of values of y. This calls for nested while expressions as illustrated below.

int x = 0, n, m ;

while ( x < n)

{

   int y = O;

          while (y < m)

     {

        statements

         y++;

      }

         x++;

}

Program illustrates the functioning of a nested while loop.

#include <stdio.h> 
 main() 
 { 
    int x =0 , Z ; 
    printf("x\ty\tZ\n"); 
    while (x<3) 
    { 
       int y = 0; 
       while (y <=3) 
         { 
            Z = x*x*x+ 2*x*y + y*y*y; 
            printf("%d\t%d\t%d\n", x, y,Z); 
            y++ ; 
         } 
            x++; 
    } 
 }