• The for loop is a widely used loop structure in C that allows you to execute a block of code repeatedly for a specified number of times.
• It consists of three parts: initialization, condition, and increment/decrement.

Syntax of a for loop in C:

for (initialization; condition; increment/decrement) {
    // code to be executed
}

Here’s a breakdown of each part:

• Initialization: It is an expression that initializes the loop control variable. It is executed only once at the beginning of the loop.
• Condition: It is a Boolean expression that is checked before each iteration. If the condition is true, the loop continues; otherwise, the loop is terminated.
• Increment/Decrement: It is an expression that updates the loop control variable after each iteration. It is executed at the end of each iteration.

Example:

#include <stdio.h>

int main() {
    for (int i = 1; i <= 5; i++) {
        printf("Iteration %d\n", i);
    }

    return 0;
}

Explanation:

• In this example, the loop control variable i is initialized to 1.
• The loop continues as long as i is less than or equal to 5.
• After each iteration, the value of i is incremented by 1.
• The loop executes the code block inside it (printing the iteration number) for each iteration.

Output:

Iteration 1
Iteration 2
Iteration 3
Iteration 4
Iteration 5

Practice problems in for loop:

Problem 1: Print Numbers in a Range

Write a program that prints all the numbers from a given start value to an end value.

#include <stdio.h>

int main() {
    int start, end;

    printf("Enter the start value: ");
    scanf("%d", &start);

    printf("Enter the end value: ");
    scanf("%d", &end);

    for (int i = start; i <= end; i++) {
        printf("%d ", i);
    }

    return 0;
}

Explanation:

• The program takes input from the user for the start and end values.
• The for loop is used to iterate from the start value to the end value.
• The loop control variable i is initialized to the start value, and the loop continues as long as i is less than or equal to the end value.
• In each iteration, the value of i is printed.
• The loop iterates until i reaches the end value.

Enter the start value: 5
Enter the end value: 9
5 6 7 8 9