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Expression.NewArrayInit Method (Type, Expression[])

Creates a NewArrayExpression that represents creating a one-dimensional array and initializing it from a list of elements.

Namespace:  System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

public static NewArrayExpression NewArrayInit(
	Type type,
	params Expression[] initializers


Type: System.Type

A Type that represents the element type of the array.

Type: System.Linq.Expressions.Expression[]

An array of Expression objects to use to populate the Expressions collection.

Return Value

Type: System.Linq.Expressions.NewArrayExpression
A NewArrayExpression that has the NodeType property equal to NewArrayInit and the Expressions property set to the specified value.


type or initializers is null.


An element of initializers is null.


The Type property of an element of initializers represents a type that is not assignable to the type type.

The Type property of each element of initializers must represent a type that is assignable to the type represented by type, possibly after it is quoted.


An element will be quoted only if type is Expression. Quoting means the element is wrapped in a Quote node. The resulting node is a UnaryExpression whose Operand property is the element of initializers.

The Type property of the resulting NewArrayExpression represents an array type whose rank is 1 and whose element type is type.

The following example demonstrates how to use the NewArrayInit method to create an expression tree that represents creating a one-dimensional string array that is initialized with a list of string expressions.

List<System.Linq.Expressions.Expression> trees =
    new List<System.Linq.Expressions.Expression>()
        { System.Linq.Expressions.Expression.Constant("oak"),
          System.Linq.Expressions.Expression.Constant("alder") };

// Create an expression tree that represents creating and   
// initializing a one-dimensional array of type string.
System.Linq.Expressions.NewArrayExpression newArrayExpression =
    System.Linq.Expressions.Expression.NewArrayInit(typeof(string), trees);

// Output the string representation of the Expression.

// This code produces the following output: 
// new [] {"oak", "fir", "spruce", "alder"}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5