Expression.NewArrayInit Method (Type, IEnumerable<Expression>)


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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,
	IEnumerable<Expression> initializers


Type: System.Type

A Type that represents the element type of the array.

Type: System.Collections.Generic.IEnumerable<Expression>

An IEnumerable<T> that contains 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.

Exception Condition

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 that type represents.

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"}

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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