Exit Controlled Loops in C

In C programming, exit controlled loops allow you to exit a loop based on a specific condition. This type of loop is commonly used when you want to exit the loop based on a condition that is checked at the end of each iteration. In this lesson, we'll explore how to use exit controlled loops in C, provide examples of their usage, and discuss their advantages and limitations.

Usage of Exit Controlled Loops

The most common type of exit controlled loop in C is the do-while loop. In a do-while loop, the loop body is executed at least once, and the condition is checked at the end of each iteration. If the condition is true, the loop continues; otherwise, the loop is exited.

do {
    // Code statements
} while (condition);

The loop body is enclosed within the do and while keywords. The condition is checked at the end of each iteration to determine whether to continue or exit the loop.

Examples of Exit Controlled Loops

Let's see a few examples to understand the usage of exit controlled loops in C:

#include <stdio.h>

int main() {
    int number;
    
    do {
        printf("Enter a number (0 to exit): ");
        scanf("%d", &number);
        
        // Perform some operations based on the number
        
    } while (number != 0);
    
    printf("Exited the loop.\n");
    
    return 0;
}

In this example, the program prompts the user to enter a number. If the number is not equal to 0, some operations are performed, and the loop continues. Once the user enters 0, the condition becomes false, and the loop is exited.

Conclusion

Exit controlled loops in C provide a way to exit a loop based on a specific condition. The do-while loop is commonly used for exit controlled loops, as it ensures that the loop body is executed at least once. Exit controlled loops are useful when you want to perform operations until a specific condition is met. However, it's important to ensure that the condition is appropriately updated within the loop to prevent infinite loops. Understanding exit controlled loops in C will enable you to write more flexible and efficient programs.