The do while Loop in C

C programming mein agar tumhe koi kaam at least ek baar to karna hi hai, uske baad condition check karni hai, to do while loop use hota hai.

Yeh while loop ki tarah hi hai, bas isme condition check baad mein hoti hai.

What is do while loop ?

do while loop ek exit-controlled loop hota hai. Matlab pehle code chalega, fir condition check hogi. Agar condition true hai to dobara chalega, warna bas ek baar hi chalega.

Syntex:

do {
    // body
} while(condition); // Condition

• Pehle do block chalega.
• Fir while(condition) check hogi.
• Jab tak condition true hai, loop repeat hota rahega.
• Condition false hone pe loop ruk jaata hai.

Example: 1 to 5 number print.

#include <stdio.h>

int main() {
    int i = 1;

    do {
        printf("%d", i);
        i++;
    } while(i <= 5);

    return 0;
}

Output:

1

2

3

4

5

Understand Line-by-Line

1. i = 1 se shuruaat ho rahi hai.
2. do ke andar ka code bina kisi checking ke ek baar chal gaya.
3. Fir i print hua aur i++ se uski value badh gayi.
4. Ab condition check hui: i <= 5. Agar true hai to loop fir se chalega.
5. Jab i = 6 ho jaayega to condition false ho jaayegi aur loop ruk jaayega.

Important Notes:

• Is loop ka code ek baar to hamesha chalega, chahe condition pehle hi false ho.
• ; semi-colon condition ke baad likhna mandatory hota hai (yeh galti log aksar karte hain).
• Condition aur increment ka dhyan rakhna varna loop kabhi rukega hi nahi.

When to use do while loop?

• Jab hume code kam se kam ek baar run karna hi karna ho.
• Jaise koi menu dikhana ya user input lena, fir uske hisaab se decide karna loop chale ya na chale.

Real Life Example

Socho tum pizza khane jaate ho aur tum bolte ho: "Main ek slice to khaunga hi, agar aur bhookh lagi to fir aur khaunga. " Bas wahi logic hai do { } while(condition) ka.