C# Program to find the cube of elements in a list

This program demonstrates how to find the cube of each element in a list using the Select() method with a lambda expression. The Select() method transforms each element in the collection by applying a specified function.

Syntax

Following is the syntax for using Select() method with lambda expression −

collection.Select(x => expression)

For calculating the cube of each element −

list.Select(x => x * x * x)

Using Select() Method to Calculate Cube

The Select() method applies a transformation function to each element in the list. In this case, we use a lambda expression c => c * c * c to calculate the cube of each element −

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

public class Demo {
    public static void Main() {
        List<int> list = new List<int> { 2, 4, 5, 7 };
        Console.WriteLine("Elements...");
        
        // Display initial list
        foreach (int n in list)
            Console.WriteLine(n);
        
        // Calculate cube of each element
        IEnumerable<int> res = list.Select(c => c * c * c);
        Console.WriteLine("Cube of each element...");
        
        foreach (int n in res)
            Console.WriteLine(n);
    }
}

The output of the above code is −

Elements...
2
4
5
7
Cube of each element...
8
64
125
343

Using Math.Pow() Method

Alternatively, you can use the Math.Pow() method to calculate the cube −

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

public class Demo {
    public static void Main() {
        List<int> numbers = new List<int> { 3, 6, 8, 10 };
        Console.WriteLine("Original numbers:");
        
        foreach (int num in numbers)
            Console.WriteLine(num);
        
        // Using Math.Pow to calculate cube
        var cubes = numbers.Select(x => (int)Math.Pow(x, 3));
        Console.WriteLine("Cubes using Math.Pow:");
        
        foreach (int cube in cubes)
            Console.WriteLine(cube);
    }
}

The output of the above code is −

Original numbers:
3
6
8
10
Cubes using Math.Pow:
27
216
512
1000

Converting to List

Since Select() returns an IEnumerable, you can convert the result to a list using ToList() method −

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

public class Demo {
    public static void Main() {
        List<int> originalList = new List<int> { 1, 2, 3, 4, 5 };
        
        // Convert result to List
        List<int> cubesList = originalList.Select(x => x * x * x).ToList();
        
        Console.WriteLine("Original: " + string.Join(", ", originalList));
        Console.WriteLine("Cubes: " + string.Join(", ", cubesList));
        Console.WriteLine("Count of cubes: " + cubesList.Count);
    }
}

The output of the above code is −

Original: 1, 2, 3, 4, 5
Cubes: 1, 8, 27, 64, 125
Count of cubes: 5

Conclusion

The Select() method with lambda expressions provides a clean and efficient way to transform elements in a collection. You can calculate cubes using simple multiplication or the Math.Pow() method, and convert the result to a list when needed for further operations.