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Expression.Multiply Method (Expression, Expression)

Creates a BinaryExpression that represents an arithmetic multiplication operation that does not have overflow checking.

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

'Declaration
Public Shared Function Multiply ( _
	left As Expression, _
	right As Expression _
) As BinaryExpression

Parameters

left
Type: System.Linq.Expressions.Expression

An Expression to set the Left property equal to.

right
Type: System.Linq.Expressions.Expression

An Expression to set the Right property equal to.

Return Value

Type: System.Linq.Expressions.BinaryExpression
A BinaryExpression that has the NodeType property equal to Multiply and the Left and Right properties set to the specified values.

ExceptionCondition
ArgumentNullException

left or right is Nothing.

InvalidOperationException

The multiplication operator is not defined for left.Type and right.Type.

The resulting BinaryExpression has the Method property set to the implementing method. The Type property is set to the type of the node. If the node is lifted, the IsLifted and IsLiftedToNull properties are both true. Otherwise, they are false. The Conversion property is Nothing.

The following information describes the implementing method, the node type, and whether a node is lifted.

The following rules determine the selected implementing method for the operation:

  • If the Type property of either left or right represents a user-defined type that overloads the multiplication operator, the MethodInfo that represents that method is the implementing method.

  • Otherwise, if left.Type and right.Type are numeric types, the implementing method is Nothing.

If the implementing method is not Nothing:

  • If left.Type and right.Type are assignable to the corresponding argument types of the implementing method, the node is not lifted. The type of the node is the return type of the implementing method.

  • If the following two conditions are satisfied, the node is lifted and the type of the node is the nullable type that corresponds to the return type of the implementing method:

    • left.Type and right.Type are both value types of which at least one is nullable and the corresponding non-nullable types are equal to the corresponding argument types of the implementing method.

    • The return type of the implementing method is a non-nullable value type.

If the implementing method is Nothing:

  • If left.Type and right.Type are both non-nullable, the node is not lifted. The type of the node is the result type of the predefined multiplication operator.

  • If left.Type and right.Type are both nullable, the node is lifted. The type of the node is the nullable type that corresponds to the result type of the predefined multiplication operator.

The following code example shows how to create an expression that multiplies two values.

' Add the following directive to your file: 
' Imports System.Linq.Expressions   

' This expression multiplies its two arguments. 
' Both arguments must be of the same type. 
Dim multiplyExpr As Expression = Expression.Multiply(
    Expression.Constant(10),
    Expression.Constant(4)
)

' Print the expression.
Console.WriteLine(multiplyExpr.ToString())

' The following statement first creates an expression tree, 
' then compiles it, and then executes it.
Console.WriteLine(
    Expression.Lambda(Of Func(Of Integer))(multiplyExpr).Compile()())

' This code example produces the following output: 

' (10*4) 
' 40

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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