Decrement Method (Expression)
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Expression.Decrement Method (Expression)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Creates a UnaryExpression that represents the decrementing of the expression by 1.

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

'Declaration
Public Shared Function Decrement ( _
	expression As Expression _
) As UnaryExpression

Parameters

expression
Type: System.Linq.Expressions.Expression
An Expression to decrement.

Return Value

Type: System.Linq.Expressions.UnaryExpression
A UnaryExpression that represents the decremented expression.

This expression is functional and does not change the value of the object passed to it.

The following code example shows how to create an expression that substracts 1 from a given value.


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

Dim num As Double = 5.5

' This expression represents a decrement operation 
' that subtracts 1 from a value. 
Dim decrementExpr As Expression = Expression.Decrement(
                            Expression.Constant(num)
                        )

' Print the expression.
outputBlock.Text &= decrementExpr.ToString() & vbCrLf

' The following statement first creates an expression tree,
' then compiles it, and then executes it.
outputBlock.Text &=
    Expression.Lambda(Of Func(Of Double))(decrementExpr).Compile()() & vbCrLf

' The value of the variable did not change,
' because the expression is functional.
outputBlock.Text &= "object: " & num & vbCrLf

' This code example produces the following output:
'
' Decrement(5.5)
' 4.5
' object: 5.5


Windows Phone OS

Supported in: 8.1, 8.0

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