Q.Write a C program to find the sum of the first n integers. The textbook presents this worked program, transcribed exactly as printed (including its printed errors):

#include <stdio.h>  
void main()  
{  
int n, i, sum=0;  
printf("Enter the value of N\n");  
scanf("%d", &n);  
i=1;  
while (i<=n)  
{  
    sum=sum+i;  
    i++;  
}  
    /* End of while */  
Printf("sum=%6d\n", sum);  
}  
    /* End of main() */  

Sample output printed in the textbook:

Enter the value of N  
6  
Sum = 21  

Loop (iterative) control statements repeat a block of statements as long as a condition holds, which lets a program perform a task many times without rewriting it. C provides three loops.

• while loop - an entry-controlled loop: the condition is tested first, so the body may run zero times.

  while (condition)
  { ... }
  

• do-while loop - an exit-controlled loop: the body runs once first and the condition is tested afterwards, so it always executes at least once.

  do
  { ... }
  while (condition);
  

• for loop - a compact loop that gathers the initialisation, test and update in one line: for (i=1; i<=n; i++). It is the natural choice when the number of repetitions is known.

Loops are used to add a series of numbers, print a name a fixed number of times, or process a menu repeatedly.

Jump statements change this normal flow from inside a loop: …