C# ToArray


ToArray converts types to arrays. It forces the evaluation of query expressions and IEnumerable types.
Implemented in System.Linq,
it reduces program length
and increases program simplicity.



LINQ: language integrated query

This program shows a query expression using the query syntax. The program takes an input integer array. It then sorts it using the LINQ syntax, which internally drills down to a quick sort.


Note:The query is not immediately executed. But the ToArray method forces its evaluation (with iteration) into an array variable.

Array:In an array, elements are stored in contiguous memory on the managed heap. The program then displays these sorted array elements.

Based on:

.NET 4.5

C# program that uses ToArray extension method

using System;
using System.Linq;

class Program
    static void Main()
	// An example array.
	int[] array1 = { 5, 4, 1, 2, 3 };
	// Use query expression on array.
	var query = from element in array1
		    orderby element
		    select element;
	// Convert expression to array variable.
	int[] array2 = query.ToArray();
	// Display array.
	foreach (int value in array2)


Var keyword

In this example, var is a perfect fit for the query expression that declares a sort of the array input element integers. After the query expression is declared and the supporting data structures are stored in memory, it is executed.

VarC# programming language

Next, the ToArray method forces evaluation. The second int[] local variable is assigned to the memory allocated on the managed heap by the internal implementation of the ToArray method.

Int Array

Tip:The ToArray extension method is a generic method that internally allocates a Buffer array where the elements are copied.

Generic Method


Squares: abstract

There are other ToArray methods in the .NET Framework. It is important to realize that the "ToArray" method identifier is used by various different implementations on different types.

Note:The List generic type has a ToArray method that is implemented on the List type.


However:You can invoke the ToArray extension method on the List type, which does the same thing but has some performance disadvantages.

Convert List, Array

Also:The ArrayList class contains a ToArray method that is implemented on its custom type.



ToArray converts an enumerable types into an array. This extension method is part of the System.Linq namespace. It can act upon a query expression variable. It forces evaluation of a query expression.