C# While Loop: A Comprehensive Guide with Examples

Introduction to C# While Loop

In C#, a while loop is a control flow statement that repeatedly executes a block of code as long as a specified condition is true. It provides a way to iterate over a block of code based on the evaluation of a condition.

Syntax of a While Loop in C

The syntax of a while loop in C# is as follows:

while (condition)
{
    // Code to be executed repeatedly
}

The condition is a Boolean expression that determines whether the loop should continue or not. As long as the condition evaluates to true, the code inside the loop will be executed.

Example: Using a While Loop in C

Let’s explore a simple example to understand how a while loop works in C#. Suppose we want to print the numbers from 1 to 5.

int number = 1;

while (number <= 5)
{
    Console.WriteLine(number);
    number++;
}

Output:

1
2
3
4
5

In this example, we initialize a variable number to 1. The while loop checks the condition number <= 5 and executes the code block inside the loop. It prints the current value of number and then increments it by 1. This process continues until the condition becomes false.

Exploring Different Use Cases of While Loop

1. Iterating over an Array

A while loop can be useful for iterating over an array and performing certain operations on each element. Here’s an example that calculates the sum of all elements in an array:

int[] numbers = { 1, 2, 3, 4, 5 };
int sum = 0;
int index = 0;

while (index < numbers.Length)
{
    sum += numbers[index];
    index++;
}

Console.WriteLine("Sum: " + sum);

Output:

Sum: 15

In this example, we use a while loop to iterate over the array numbers. The loop starts with index as 0 and continues until index reaches the length of the array. We accumulate the sum of all elements in the variable sum.

2. User Input Validation

While loops are commonly used for input validation, where we repeatedly prompt the user until they provide valid input. Consider the following example that asks the user to enter a positive number:

int number = -1;

while (number <= 0)
{
    Console.WriteLine("Enter a positive number:");
    string input = Console.ReadLine();
    int.TryParse(input, out number);
}

Console.WriteLine("You entered: " + number);

In this code, the while loop continues until the user enters a positive number. We prompt the user to enter a number and validate it using int.TryParse(). If the input is not a valid integer or if it’s less than or equal to 0, the loop iterates again.

Conclusion

The while loop in C# is a powerful construct for repetitive execution of code blocks based on a condition. It allows developers to control the flow of their programs and perform various tasks efficiently. By understanding the syntax and examples provided in this article, you should now have a solid understanding of how to use while loops in C#.

Frequently Asked Questions

What is a while loop in C#?

A while loop in C# is a control flow statement that repeatedly executes a block of code as long as a specified condition is true.

What is the correct syntax for a while loop in C#?

The syntax of a while loop in C# is as follows:
while (condition)
{
// Code to be executed repeatedly
}

What is the difference between a loop and a while loop in C#?

A loop is a general term that refers to any construct used to repeatedly execute a block of code. On the other hand, a while loop is a specific type of loop in C# that executes the code block as long as a condition is true.

How to use while in C#?

To use a while loop in C#, you need to specify a condition that determines whether the loop should continue or not. The code inside the loop will be executed repeatedly as long as the condition evaluates to true.

How does a while () loop work?

A while loop works by evaluating a condition before each iteration. If the condition is true, the code block inside the loop is executed. After each iteration, the condition is re-evaluated, and if it remains true, the loop continues. Once the condition becomes false, the loop terminates.

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