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Expression.Return Method (LabelTarget, Expression)

Creates a GotoExpression representing a return statement. The value passed to the label upon jumping can be specified.

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

public static GotoExpression Return(
	LabelTarget target,
	Expression value
)

Parameters

target
Type: System.Linq.Expressions.LabelTarget

The LabelTarget that the GotoExpression will jump to.

value
Type: System.Linq.Expressions.Expression

The value that will be passed to the associated label upon jumping.

Return Value

Type: System.Linq.Expressions.GotoExpression
A GotoExpression with Kind equal to Continue, the Target property set to target, and value to be passed to the target label upon jumping.

The following example demonstrates how to create an expression that contains the Return method.

// Add the following directive to the file: 
// using System.Linq.Expressions;   

// A label expression of the void type that is the target for Expression.Return().
LabelTarget returnTarget = Expression.Label();

// This block contains a GotoExpression that represents a return statement with no value. 
// It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression. 
// The types of the GotoExpression, label expression, and LabelTarget must match.
BlockExpression blockExpr =
    Expression.Block(
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Return")),
        Expression.Return(returnTarget),
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Other Work")),
        Expression.Label(returnTarget)
    );

// The following statement first creates an expression tree, 
// then compiles it, and then runs it.
Expression.Lambda<Action>(blockExpr).Compile()();

// This code example produces the following output: 
// 
// Return 

// "Other Work" is not printed because 
// the Return expression transfers execution from Expression.Return(returnTarget) 
// to Expression.Label(returnTarget).

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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