Loops are fundamental in programming. They allow us to repeat a block of code multiple times, which is especially useful when dealing with repetitive tasks like processing arrays, running calculations, or displaying data.

In this article, we’ll explore the different types of loops in C#, including:

• for
• while
• do...while
• foreach

Why Use Loops?

Imagine printing numbers from 1 to 100 manually — it’s inefficient and error-prone. With loops, we can automate such tasks with just a few lines of code.

1. for Loop

The for loop is commonly used when the number of iterations is known ahead of time.

Syntax:

for (initialization; condition; increment)
{
    // Code to execute
}

Example:

for (int i = 1; i <= 5; i++)
{
    Console.WriteLine("Count: " + i);
}

Output:

Count: 1  
Count: 2  
Count: 3  
Count: 4  
Count: 5  

2. while Loop

The while loop runs as long as the condition is true. It’s useful when you don’t know how many times the loop should run.

Syntax:

while (condition)
{
    // Code to execute
}

Example:

int i = 1;
while (i <= 5)
{
    Console.WriteLine("Number: " + i);
    i++;
}

3. do...while Loop

This loop is similar to while, but it executes the code block at least once, even if the condition is false.

Syntax:

do
{
    // Code to execute
}
while (condition);

Example:

int i = 1;
do
{
    Console.WriteLine("Value: " + i);
    i++;
}
while (i <= 5);

4. foreach Loop

The foreach loop is used to iterate over collections like arrays, lists, or any enumerable data.

Syntax:

foreach (datatype item in collection)
{
    // Code to execute
}

Example:

string[] fruits = { "Apple", "Banana", "Cherry" };

foreach (string fruit in fruits)
{
    Console.WriteLine(fruit);
}

Output: 

Apple  
Banana  
Cherry  

Breaking and Continuing Loops

You can control loop execution using:

Example with break:

for (int i = 1; i <= 10; i++)
{
    if (i == 6) break;
    Console.WriteLine(i);
}

Output:

1 2 3 4 5

Example with continue:

for (int i = 1; i <= 5; i++)
{
    if (i == 3) continue;
    Console.WriteLine(i);
}

Output: 

1 2 4 5

Summary Table