C# | Array.FindAll() Method Last Updated : 03 Feb, 2023 Summarize Comments Improve Suggest changes Share Like Article Like Report This method is used to retrieve all the elements that match the conditions defined by the specified predicate.Syntax: public static T[] FindAll (T[] array, Predicate 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 an array containing all elements that matches the conditions defined by the specified predicate if it is found. Otherwise, it returns an empty array.Exception: This method throws ArgumentNullException if the array is null or match is null.Below programs illustrate the use of Array.FindAll(T[], Predicate) Method:Example 1: CSharp // C# program to demonstrate // FindAll() 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", "Sat"}; // 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 FindAll() String[] value = Array.FindAll(myArr, element => element.StartsWith("S", StringComparison.Ordinal)); // Display the value // of the found element. Console.WriteLine("Elements are: "); // printing the Array of String PrintIndexAndValues(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 Sat Elements are: Sun Sat Example 2: CSharp // C# program to demonstrate // FindAll() method // For ArgumentNullException using System; using System.Collections.Generic; public class GFG { // Main Method public static void Main() { try { // Creating and initializing // new the String String[] myArr = null; // getting a element a with // required condition using // method FindAll() Console.WriteLine("Trying to get the element from a null array"); Console.WriteLine(); String[] value = Array.FindAll(myArr, element => element.StartsWith("S", StringComparison.Ordinal)); // Display the value of the found element. Console.WriteLine("Elements are: "); // printing the Array of String PrintIndexAndValues(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: Trying to get the element from a null array Exception Thrown: System.ArgumentNullException Reference: https://docs.microsoft.com/en-us/dotnet/api/system.array.findall?view=netframework-4.7.2 Comment More infoAdvertise with us Next Article C# | Array.LastIndexOf(T[], T) Method R rohitprasad3 Follow Improve Article Tags : C# CSharp-method CSharp-Arrays Similar Reads 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. 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