Do while loop example in c?

Do While Loop Example in C

Introduction

The do-while loop is a type of for loop that is used to execute a block of code repeatedly while a certain condition is true. It is a versatile and powerful tool that is widely used in programming languages, including C. In this article, we will explore the do-while loop in C, its syntax, and its usage.

Syntax

The do-while loop is defined as follows:

do {

    // code to be executed

} while (condition);

• The do keyword is used to start the loop.
• The while keyword is used to define the condition.
• The condition is a boolean expression that is evaluated before each iteration of the loop.

Example

Let’s consider an example to understand the do-while loop in C.

#include <stdio.h>



int main() {

    int i = 0;

    int j = 0;



    // Initialize variables

    printf("Enter the number of iterations: ");

    scanf("%d", &i);



    // Loop until the condition is true

    do {

        printf("Iteration %d: ", i);

        scanf("%d", &j);

        printf("Value of j: %dn", j);

        i++;

    } while (i < 5);



    return 0;

}

How it Works

Here’s a step-by-step explanation of how the do-while loop works:

1. The program starts by asking the user to enter the number of iterations.
2. The user enters the number of iterations, which is stored in the variable i.
3. The program then enters the do loop, which executes the code inside the loop.
4. In each iteration of the loop, the program asks the user to enter the value of j.
5. The value of j is stored in the variable j.
6. The program then increments the value of i by 1.
7. The loop continues until the condition i < 5 is false.
8. At this point, the program exits the do loop and returns to the while loop.

Key Points

• The do-while loop is used to execute a block of code repeatedly while a certain condition is true.
• The condition is evaluated before each iteration of the loop.
• The do keyword is used to start the loop, and the while keyword is used to define the condition.
• The condition is a boolean expression that is evaluated before each iteration of the loop.
• The do-while loop is useful when you want to execute a block of code repeatedly while a certain condition is true.

Advantages

• The do-while loop is more efficient than the while loop because it eliminates the need to check the condition before each iteration.
• The do-while loop is also more concise than the while loop because it eliminates the need to write a separate if statement.

Disadvantages

• The do-while loop can be less readable than the while loop because it does not provide a clear indication of the loop’s termination.
• The do-while loop can be less efficient than the while loop because it does not provide a clear indication of the loop’s termination.

Conclusion

In conclusion, the do-while loop is a powerful and versatile tool that is widely used in programming languages, including C. Its syntax is simple and easy to understand, and its usage is straightforward. The do-while loop is useful when you want to execute a block of code repeatedly while a certain condition is true. Its advantages include efficiency and conciseness, while its disadvantages include lack of readability and efficiency.