C# | Converting an array of one type to an array of another type (original) (raw)

Last Updated : 01 Feb, 2019

Array.ConvertAll(TInput[], Converter<TInput, TOutput>) Method is used to convert an array of one type to an array of another type.Syntax:

public static TOutput[] ConvertAll<TInput,TOutput> (TInput[] array, Converter<TInput,TOutput> converter);

Here, TInput and TOutput is the source array and target array respectively.Parameters:

array: It is the one-dimensional, zero-based Array to convert to a target type.converter: It is a Converter that converts each element from one type to another type.

Return Value: This method returns an array of the target type containing the converted elements from the source array.Exception: This method throws ArgumentNullException if the array is null or converter is null. Below programs illustrate the use of Array.ConvertAll(TInput[], Converter<TInput, TOutput>) Method Example 1:

CSHARP `

// C# program to demonstrate // Array.ConvertAll() Method using System; using System.Collections.Generic;

public class GFG {

// Main Method
public static void Main()
{

    try {

        // Creating and initializing
        // new the Array of int
        int[] myArr = {10, 20, 30, 40};

        // Display the values of the myArr.
        Console.WriteLine("Initial Array:");

        // calling the PrintIndexAndValues()
        // method to print
        PrintIndexAndValues(myArr);

        // converting int myArr to String conarr
        String[] conarr = Array.ConvertAll(myArr, 
          new Converter<int, String>(intToString));

        // Display the values of the myArr.
        Console.WriteLine("Converted Array:");

        // calling the PrintIndexAndValues()
        // method to print
        PrintIndexAndValues(conarr);
    }
    catch (ArgumentNullException e) {

        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}

// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(String[] myArr)
{
    for (int i = 0; i < myArr.Length; i++) {

        Console.WriteLine("{0}", myArr[i]);
    }
    Console.WriteLine();
}

// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(int[] myArr)
{
    for (int i = 0; i < myArr.Length; i++) {

        Console.WriteLine("{0}", myArr[i]);
    }
    Console.WriteLine();
}

// Defining the method
// intToString
public static String intToString(int pf)
{
    return pf.ToString();
}

}

`

Output:

Initial Array: 10 20 30 40

Converted Array: 10 20 30 40

Example 2:

CSHARP `

// C# program to demonstrate // Array.ConvertAll() Method using System; using System.Collections.Generic;

public class GFG {

// Main Method
public static void Main()
{

    try {

        // Creating and initializing new 
        // the Array of int with null value
        int[] myArr = null;

        // converting int myArr to String conarr
        String[] conarr = Array.ConvertAll(myArr, 
         new Converter<int, String>(intToString));

        // calling the PrintIndexAndValues()
        // method to print
        PrintIndexAndValues(conarr);
    }
    catch (ArgumentNullException e) {

        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}

// Defining the method
// PrintIndexAndValues
public static void PrintIndexAndValues(String[] myArr)
{
    for (int i = 0; i < myArr.Length; i++) {

        Console.WriteLine("{0}", myArr[i]);
    }
    Console.WriteLine();
}

// Defining the method
// intToString
public static String intToString(int pf)
{
    return pf.ToString();
}

}

`

Output:

Exception Thrown: System.ArgumentNullException

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.array.convertall?view=netframework-4.7.2