While Loop

C Programming Tutorial : While Loop

Welcome to the "Codes with Pankaj While Loop in C Programming" tutorial ! This tutorial will guide you through the concepts and practical applications of the while loop in C.

Table of Contents

1. Introduction to While Loop

2. Syntax of While Loop

3. Flowchart of While Loop

4. Examples of While Loop

5. Common Mistakes and Best Practices

6. Exercises

---

1. Introduction to While Loop

A while loop in C programming is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop checks the condition before executing the loop's body.

2. Syntax of While Loop

The basic syntax of the while loop in C is as follows:

while (condition) {
    // code to be executed
}

• condition: An expression that evaluates to true or false.

• If the condition is true, the code within the loop is executed.

• If the condition is false, the loop terminates, and control passes to the statement following the loop.

3. Flowchart of While Loop

Below is a simple flowchart that illustrates the working of a while loop:

4. Examples of While Loop

Let's look at a few examples to understand the while loop better.

Example 1: Basic While Loop

This example demonstrates a basic while loop that prints numbers from 1 to 5.

#include <stdio.h>

int main() {
    int i = 1;
    while (i <= 5) {
        printf("%d\n", i);
        i++;
    }
    return 0;
}

Example 2: Sum of Natural Numbers

This example calculates the sum of the first 10 natural numbers.

#include <stdio.h>

int main() {
    int i = 1, sum = 0;
    while (i <= 10) {
        sum += i;
        i++;
    }
    printf("Sum of first 10 natural numbers: %d\n", sum);
    return 0;
}

Example 3: Infinite Loop

An example of an infinite loop. Be careful with such loops as they can cause your program to run indefinitely.

#include <stdio.h>

int main() {
    while (1) {
        printf("This loop will run forever.\n");
    }
    return 0;
}

5. Common Mistakes and Best Practices

Common Mistakes

1. Forgetting to Update the Loop Variable: If you forget to update the loop variable, it may result in an infinite loop.

   int i = 1;
   while (i <= 5) {
       printf("%d\n", i);
       // i++; // Uncomment this to fix the infinite loop
   }

2. Using Incorrect Condition: Ensure that the condition eventually becomes false to avoid infinite loops.

Best Practices

1. Initialize Variables Properly: Always initialize the loop control variables before the loop.

2. Update Loop Variables: Ensure that loop control variables are updated appropriately within the loop.

3. Avoid Infinite Loops: Be cautious with conditions that can cause infinite loops.

6. Exercises

Try these exercises to practice while loops in C:

1. Exercise 1: Write a program to print the first 10 even numbers using a while loop.

2. Exercise 2: Write a program to calculate the factorial of a number using a while loop.

3. Exercise 3: Write a program that reads integers from the user and stops when the user enters -1. The program should then print the sum of all entered numbers.

---

We hope this tutorial has helped you understand the while loop in C programming. Practice with the exercises provided to reinforce your understanding. Happy coding!

For more tutorials, visit www.codeswithpankaj.com.