Expression.Loop Method

Definition

Namespace:

System.Linq.Expressions

Assemblies:

netstandard.dll, System.Linq.Expressions.dll

Creates a LoopExpression.

Overloads

Loop(Expression)	Creates a LoopExpression with the given body.
Loop(Expression, LabelTarget)	Creates a LoopExpression with the given body and break target.
Loop(Expression, LabelTarget, LabelTarget)	Creates a LoopExpression with the given body.

Loop(Expression)

Source:

LoopExpression.cs

Creates a LoopExpression with the given body.

C#

public static System.Linq.Expressions.LoopExpression Loop(System.Linq.Expressions.Expression body);

Parameters

body

Expression

The body of the loop.

Returns

LoopExpression

The created LoopExpression.

Loop(Expression, LabelTarget)

Source:

LoopExpression.cs

Creates a LoopExpression with the given body and break target.

C#

public static System.Linq.Expressions.LoopExpression Loop(System.Linq.Expressions.Expression body, System.Linq.Expressions.LabelTarget? break);

Parameters

body

Expression

The body of the loop.

break

LabelTarget

The break target used by the loop body.

Returns

LoopExpression

The created LoopExpression.

Examples

The following example demonstrates how to create a block expression that contains a LoopExpression object.

C#

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

// Creating a parameter expression.
ParameterExpression value = Expression.Parameter(typeof(int), "value");

// Creating an expression to hold a local variable.
ParameterExpression result = Expression.Parameter(typeof(int), "result");

// Creating a label to jump to from a loop.
LabelTarget label = Expression.Label(typeof(int));

// Creating a method body.
BlockExpression block = Expression.Block(
    new[] { result },
    Expression.Assign(result, Expression.Constant(1)),
        Expression.Loop(
           Expression.IfThenElse(
               Expression.GreaterThan(value, Expression.Constant(1)),
               Expression.MultiplyAssign(result,
                   Expression.PostDecrementAssign(value)),
               Expression.Break(label, result)
           ),
       label
    )
);

// Compile and run an expression tree.
int factorial = Expression.Lambda<Func<int, int>>(block, value).Compile()(5);

Console.WriteLine(factorial);

// This code example produces the following output:
//
// 120

Loop(Expression, LabelTarget, LabelTarget)

Source:

LoopExpression.cs

Creates a LoopExpression with the given body.

C#

public static System.Linq.Expressions.LoopExpression Loop(System.Linq.Expressions.Expression body, System.Linq.Expressions.LabelTarget? break, System.Linq.Expressions.LabelTarget? continue);

Parameters

body

Expression

The body of the loop.

break

LabelTarget

The break target used by the loop body.

continue

LabelTarget

The continue target used by the loop body.

Returns

LoopExpression

The created LoopExpression.