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Sujith V S
Sujith V S

Posted on • Edited on

Loops in C programming

In C programming there are 3 types of loop and they are while loop, for loop and do while loop.

While loop

In while loop the body is executed until the test condition become false.
Syntax:

while (conditiuon){
    //statement inside while.
}
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Example:

#include <stdio.h>
int main() {
    int count = 1;

    while (count < 5){
        printf("While loop in c\n");
        count = count + 1;
    }

    return 0;
}
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Multiplication table using while loop:

#include <stdio.h>

int main() {
    int number;
    printf("Enter the number: ");
    scanf("%d", &number);

    int count = 1;
    while(count <= 10){
        int product = number * count;
        printf("%d x %d = %d \n", count, number, product);
        count = count + 1;
    }
    return 0;
}
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do while loop

Here the body of the loop is executed and then the condition is evaluated, if the condition is true the body of the loop is executed again.
syntax:

do {
  //body of loop
  } while(condition);
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Example:

int main(){

    int count = 5;

    do{
        printf("%d\n", count);
        count = count + 1;
    } while(count < 5);
    return 0;
}
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for loop

Syntax:

for(initializationExpression; testExpression; updateExpression){
//codee inside for loop.
}
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Example:

int main() {

    for(int i=0; i<10; i++){
        printf("%d ", i);
    }
    return 0;
}
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Sum of whole numbers from 1 to 100:

int main() {
    int sum=0;

    for(int i=1; i<=100; i++){
        sum=sum+i;

    }
    printf("%d", sum);
    return 0;
}
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Sum of even numbers:

int main() {
    int sum=0;

    for(int i=2; i<=100; i=i+2){
        sum=sum+i;
    }

    printf("%d", sum);
    return 0;
}
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