Loop in C Programming

A loop in C programming is a control flow structure that allows you to repeat a block of code multiple times until a specific condition is met.
Loop Consists three points:

• Iterating through data: Working with sequences of data, such as arrays or lists.
• Repeated calculations or actions: Performing the same task a specified number of times or until a condition is reached.
• Input validation: Repeatedly requesting and validating user input until it meets specific criteria.

for Loop

In for loop first it check condition and then if the condition is satisfy then its body part is execute and then updation is happen.at last if condition false and loop will terminate.

for( initial value; condition; incrementation or decrementation )
{
    //statement
    //statement
}

• Initialization: A statement executed once before the loop begins. Typically used to set up a counter variable.
• Condition: An expression evaluated before each iteration. The loop continues to run only if this condition is true (non-zero).
• Increment/decrement: A statement executed after each iteration. This is often used to update the counter variable.

• Initialization: The initialization statement runs once.
• Condition Check: The condition is evaluated. If it's true, the code block within the loop executes. If not, the loop terminates.
• Code Execution: The code within the loop's body runs.
• Increment/Decrement: The increment/decrement statement is executed.
• Back to Step 2: The process repeats from step 2 (condition check) until the condition becomes false.

#include<stdio.h>
int main()
{
    int x=10,i;
    for(i=0;i<=x;i++)
    {
        printf("%d\t",i);
    }
}

0 1 2 3 4 5 6 7 8 9 10

In first time at i=0 then it check condition and then if the condition is satisfy then its body part is execute and then updation is happen.at last at x=11 condition false and loop is terminate.

while loop

In while loop first it checks the condition and body part execute and then updation is happen.At last if condition is false and loop will terminate.

while(condition)
{
    //statement
    //statement
    incrementation or decrementation;
 }

#include<stdio.h>
int main()
{
    int x=10,i=0;
    while(i<x)
    {
        printf("%d\t",i);
        i++;
    }
}

0 1 2 3 4 5 6 7 8 9 10

Here the initially x=10 and i=0 first it check the condition and then body part execute then updation is happen.At last at i=11 condition is false and loop will terminate.

do-while loop

In do-while loop first body part execute then updation is happen after that condition checked.

do{
    //statement
    //statement
    incrementation or decrementation;
}while( condition );

#include<stdio.h>
int main()
{
    int x=10,i=0;
    do{
        printf("%d",i);
    }while(i<=10);
}

0 1 2 3 4 5 6 7 8 9 10 11

Here the initially x=10 and i=0 first body part execute then updation is happen after that condition checked.

Difference Between for,while and do-while