How to Get the Index of the Current Iteration of a Foreach Loop in C#

1. C# Program to Get the index of the Current Iteration of a foreach Loop Using Select() Method
2. C# Program to Get the index of the Current Iteration of a foreach Loop Using index variable Method

In C#, we have mainly two loops, for loop and foreach loop. The foreach loop is considered to be the best because it is suitable for all types of operations. Even for the ones in which we do not need the index value.

There are some cases in which we need to use the foreach loop but we also have to get the index number. To solve this problem, in C#, we have different methods to get the index of the current iteration of a foreach loop, for example, Select() and index variable method.

C# Program to Get the index of the Current Iteration of a foreach Loop Using Select() Method

The method Select() is a LINQ method. LINQ is a part of C# that is used to access different databases and data sources. The Select() method selects the value and index of the iteration of a foreach loop.

The correct syntax to use this method is as follows:

Select((Value, Index) => new { Value, Index });

Example Code:

using System;
using System.Linq;
using System.Collections.Generic;

public class IndexOfIteration {
  public static void Main() {
    // Creating integer List
    List<int> Numbers = new List<int>() { 1, 2, 3, 4, 8, 10 };
    // Visiting each value of List using foreach loop
    foreach (var New in Numbers.Select((value, index) => new { value, index })) {
      Console.WriteLine("The Index of Iteration is: {0}", New.index);
    }
  }
}

Output:

The Index of Iteration is: 0
The Index of Iteration is: 1
The Index of Iteration is: 2
The Index of Iteration is: 3
The Index of Iteration is: 4
The Index of Iteration is: 5

C# Program to Get the index of the Current Iteration of a foreach Loop Using index variable Method

This is the traditional and the most simple method to find the index of iteration of a foreach loop. In this method, we use a variable and initialize it with zero and then do increment in its value in each iteration.

This is the most basic method. It only requires the basic knowledge of C# to implement this method.

Example Code:

using System;
using System.Collections.Generic;

public class IndexOfIteration {
  public static void Main() {
    // Creating an integer List
    List<int> Numbers = new List<int>() { 1, 2, 3, 4, 8, 10 };

    int index = 0;
    // Visiting each value of List using foreach loop
    foreach (var Number in Numbers) {
      Console.WriteLine("The Index of Iteration is {0}", index);
      index++;
    }
  }
}

Output:

The Index of Iteration is: 0
The Index of Iteration is: 1
The Index of Iteration is: 2
The Index of Iteration is: 3
The Index of Iteration is: 4
The Index of Iteration is: 5