while loop in C

while loop in C

• The while loop in C language is used to iterate the part of program or statements many times.
• In while loop, condition is given before the statement. So it is different from the do while loop. 
• It can execute the statements 0 or more times.

When use while loop in C

• The C language while loop should be used if number of iteration is uncertain or unknown.

Syntax of while loop in C language

• The syntax of while loop in c language is given below:

while(condition){  

//code to be executed  

}  

Flowchart of while loop in C

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Example of while loop in C language

• Let's see the simple program of while loop that prints table of 1.

1. #include <stdio.h>      
2. #include <conio.h>      
3. void main(){      
4. int i=1;    
5. clrscr();        
6. while(i<=10){    
7. printf("%d \n",i);    
8. i++;    
9. }     
10. getch();      
11. }      

Output

1

2

3

4

5

6

7

8

9

10

Program to print table for the given number using while loop in C

1. #include <stdio.h>    
2. #include <conio.h>    
3. void main(){    
4. int i=1,number=0;  
5. clrscr();      
6. printf("Enter a number: ");  
7. scanf("%d",&number);    
8. while(i<=10){  
9. printf("%d \n",(number*i));  
10. i++;  
11. }    
12. getch();    
13. }    

Output

Enter a number: 50

50

100

150

200

250

300

350

400

450

500

Enter a number: 100
100
200
300
400
500
600
700
800
900
1000

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Infinitive while loop in C

If you pass 1 as a expression in while loop, it will run infinite number of times.

1. while(1){  
2. //statement  
3. }