A while loop in C continuously executes the contents of its loop as long as a condition is true. The syntax for the while loop is as follows

while(condition) { statements; }

These statements can be of any nature. The important thing is that the loop executes only if the condition statement beside while gives a boolean logic output of 1. So if you remove the condition statement and place a logic 1 bit there, the while loop becomes an infinite loop.

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**Write a program using the while loop in C to print the first 10 natural numbers**

//print the first 10 natural numbers #include<stdio.h> #include<conio.h> void main() { clrscr; int i=0; while(i<=9) { printf("%d\n",++i); } getch(); }

**Write a program in C to check if a number is same after reversing it**

//take number from the user, reverse it and check whether it is the same as the original number #include<stdio.h> #include<conio.h> void main() { clrscr(); int i,temp=0,b,c; printf("Enter a number\n"); scanf("%d",&i); c=i; while(i>0) { b=i%10; i=i/10; temp=(temp*10)+b; } if(temp==c) { printf("This number is the same when reversed"); } else { printf("This number is not the same when reversed"); } getch(); }

**WAP (Write a program) in C to take a number from a user and check if the product and sum of the number’s digits are same**

//take number from user and find if sum and product of the digits is the same #include<stdio.h> #include<conio.h> void main() { clrscr(); int i,b,mul=1,sum=0; printf("Enter number\n"); scanf("%d",&i); while(i>0) { b=i%10; i=i/10; mul=mul*b; sum=sum+b; } if(mul==sum) { printf("The sum and product of the digits of this number are equal"); } else { printf("The sum and product of the digits of this number are not equal"); } getch(); }

**Write a program in C to take print the series of numbers up to 10,000 whose product and sum of the digits are same**

//print series of the numbers upto 10000 whose sum and product of the digits is the same #include<stdio.h> #include<conio.h> void main() { clrscr(); int i,b,mul=1,sum=0,temp; for(i=21;i<=10000;i++) { temp=i; while(i>0) { b=i%10; i=i/10; mul=mul*b; sum=sum+b; } if(mul==sum) { printf("%d\n",temp); } i=temp; mul=1; sum=0; } getch(); }