C# For/foreach Loop

In C#, both for and foreach loops are used to iterate over a collection of items. The main difference between them is that for loops use an index variable to iterate over a collection, while foreach loops automatically iterate over each element in a collection without the need for an index. In this tutorial, we'll cover how to use for and foreach loops in C#.

Using for loop with arrays:

Here's an example of using a for loop to iterate over an array of integers:

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

for (int i = 0; i < numbers.Length; i++)
{
    Console.WriteLine(numbers[i]);
}

The for loop uses the index variable i to access each element in the numbers array.

Using foreach loop with arrays:

Here's the same example using a foreach loop:

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

foreach (int number in numbers)
{
    Console.WriteLine(number);
}

The foreach loop iterates through each element in the numbers array, assigning the current element to the number variable.

Using for loop with lists:

You can use the for loop with collections like List<T>. Here's an example using a List<string>:

using System;
using System.Collections.Generic;

List<string> names = new List<string>() { "Alice", "Bob", "Charlie" };

for (int i = 0; i < names.Count; i++)
{
    Console.WriteLine(names[i]);
}

In this example, the for loop uses the index variable i to access each element in the names list.

Using foreach loop with lists:

Here's the same example using a foreach loop:

using System;
using System.Collections.Generic;

List<string> names = new List<string>() { "Alice", "Bob", "Charlie" };

foreach (string name in names)
{
    Console.WriteLine(name);
}

In this example, the foreach loop iterates through each element in the names list, assigning the current element to the name variable.

When to use for vs. foreach:

Use a for loop when you need to access elements by their index or when you need to modify the elements of the collection.
Use a foreach loop when you only need to read the elements of the collection or when you want a more elegant and concise way of iterating over a collection.

In this tutorial, we've covered how to use both for and foreach loops in C#. The for loop is useful when you need to access elements by their index or modify the elements, while the foreach loop provides a clean and elegant way to iterate over a collection without the need for an index variable.

How to use for loop in C#:

Description: The for loop in C# provides a concise and flexible way to iterate over a range of values.

Code:

using System;

class Program
{
    static void Main()
    {
        // Example of for loop
        for (int i = 0; i < 5; i++)
        {
            Console.WriteLine(i);
        }
    }
}

C# for loop examples:

Description: The for loop can be used in various scenarios, such as iterating over arrays, lists, or a range of values.

Code:

using System;

class Program
{
    static void Main()
    {
        // Example of for loop with an array
        int[] numbers = { 1, 2, 3, 4, 5 };

        for (int i = 0; i < numbers.Length; i++)
        {
            Console.WriteLine(numbers[i]);
        }
    }
}

C# nested for loop example:

Description: for loops can be nested to traverse elements in a two-dimensional array or perform other nested iterations.

Code:

using System;

class Program
{
    static void Main()
    {
        // Example of nested for loop
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                Console.Write($"{i}-{j} ");
            }
            Console.WriteLine();
        }
    }
}

C# for loop through a range of numbers:

Description: The for loop can easily iterate through a specified range of numbers.

Code:

using System;

class Program
{
    static void Main()
    {
        // Example of for loop through a range
        for (int i = 1; i <= 5; i++)
        {
            Console.WriteLine(i);
        }
    }
}

C# foreach loop with break and continue:

Description: The foreach loop can incorporate break and continue statements to control the flow of execution.

Code:

using System;

class Program
{
    static void Main()
    {
        int[] numbers = { 1, 2, 3, 4, 5 };

        // Example of foreach loop with break and continue
        foreach (int number in numbers)
        {
            if (number == 3)
                break; // exit the loop when 3 is encountered

            if (number % 2 == 0)
                continue; // skip even numbers

            Console.WriteLine(number);
        }
    }
}

Looping over strings with for loop in C#:

Description: for loops are suitable for iterating over characters in a string.

Code:

using System;

class Program
{
    static void Main()
    {
        string text = "C#";

        // Example of for loop with a string
        for (int i = 0; i < text.Length; i++)
        {
            Console.WriteLine(text[i]);
        }
    }
}