Enter a number.
5
Factorial=120
do...while loop
In C, do...while loop is very similar to while loop. Only difference between these two loops is that, in while loops, test expression is checked at first but, in do...while loop code is executed at first then the condition is checked. So, the code are executed at least once in do...while loops.
Syntax of do...while loops
do {
some code/s;
}
while (test expression);
At first codes inside body of do is executed. Then, the test expression is checked. If it is true, code/s inside body of do are executed again and the process continues until test expression becomes false(zero).
Notice, there is semicolon in the end of while (); in do...while loop.
Example of do...while loop
Write a C program to add all the numbers entered by a user until user enters 0.
/*C program to demonstrate the working of do...while statement*/
#include <stdio.h>
int main(){
int sum=0,num;
do /* Codes inside the body of do...while loops are at least executed
once. */
{
printf("Enter a number\n");
scanf("%d",&num);
sum+=num;
}
while(num!=0);
printf("sum=%d",sum);
return 0;
}