C# | Array.Find() Method

This method is used to search for an element that matches the conditions defined by the specified predicate and returns the first occurrence within the entire Array.

Syntax:

public static T Find (T[] array, Predicate<T> match);

Here, T is the type of element of the array.

Parameters:

array: It is the one-dimensional, zero-based array to search.

match: It is the predicate that defines the conditions of the element to search for.

Return Value: This method return the first element that matches the conditions defined by the specified predicate if it is found. Otherwise, it returns the default value for type T.

Exception: This method throws ArgumentNullException if the array is null or match is null.

Below programs illustrate the use of Array.Find(T[], Predicate) Method:

Example 1:

CSharp

// C# program to demonstrate
// Array.Find(T[], Predicate<T>)
// Method
using System;
using System.Collections.Generic;

public class GFG {

    // Main Method
    public static void Main()
    {

        try {

            // Creating and initializing new the String
            String[] myArr = {"Sun", "Mon", "Tue", "Thu"};

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

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

            // getting a element a with required
            // condition using method Find()
            string value = Array.Find(myArr,
                       element => element.StartsWith("S",
                       StringComparison.Ordinal));

            // Display the value of
            // the found element.
            Console.Write("Element: ");

            // printing the string
            // following the condition
            Console.Write("{0}", value);
        }
        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();
    }
}

Output:

Initial Array:
Sun
Mon
Tue
Thu

Element: Sun

Example 2:

CSharp

// C# program to demonstrate
// Array.Find(T[], Predicate<T>)
// Method
using System;
using System.Collections.Generic;

public class GFG {

    // Main Method
    public static void Main()
    {

        try {

            // Creating and initializing new
            // the String with the null value
            String[] myArr = null;

            // getting an element a with
            // required condition
            // using method Find()
            string value = Array.Find(myArr,
                    element => element.StartsWith("S",
                    StringComparison.Ordinal));

            // Display the value of
            // the found element.
            Console.Write("Element: ");

            // printing the string
            // following the condition
            Console.Write("{0}", value);
        }

        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();
    }
}

Output:

Exception Thrown: System.ArgumentNullException

Reference:

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