Powershell 7有这个功能。

PS C:\Users\js> 0 ? 'yes' : 'no'
no
PS C:\Users\js> 1 ? 'yes' : 'no'
yes

我能够想出的最接近PowerShell的构造是:

@({'condition is false'},{'condition is true'})[$condition]

从PowerShell版本7开始，三元运算符被内置到PowerShell中。

1 -gt 2 ? "Yes" : "No"
# Returns "No"

1 -gt 2 ? 'Yes' : $null
# Get a $null response for false-y return value

下面是另一种自定义函数方法:

function Test-TernaryOperatorCondition {
    [CmdletBinding()]
    param (
        [Parameter(ValueFromPipeline = $true, Mandatory = $true)]
        [bool]$ConditionResult
        ,
        [Parameter(Mandatory = $true, Position = 0)]
        [PSObject]$ValueIfTrue
        ,
        [Parameter(Mandatory = $true, Position = 1)]
        [ValidateSet(':')]
        [char]$Colon
        ,
        [Parameter(Mandatory = $true, Position = 2)]
        [PSObject]$ValueIfFalse
    )
    process {
        if ($ConditionResult) {
            $ValueIfTrue
        }
        else {
            $ValueIfFalse
        }
    }
}
set-alias -Name '???' -Value 'Test-TernaryOperatorCondition'

例子

1 -eq 1 |??? 'match' : 'nomatch'
1 -eq 2 |??? 'match' : 'nomatch'

差异的解释

Why is it 3 question marks instead of 1? The ? character is already an alias for Where-Object. ?? is used in other languages as a null coalescing operator, and I wanted to avoid confusion. Why do we need the pipe before the command? Since I'm utilising the pipeline to evaluate this, we still need this character to pipe the condition into our function What happens if I pass in an array? We get a result for each value; i.e. -2..2 |??? 'match' : 'nomatch' gives: match, match, nomatch, match, match (i.e. since any non-zero int evaluates to true; whilst zero evaluates to false). If you don't want that, convert the array to a bool; ([bool](-2..2)) |??? 'match' : 'nomatch' (or simply: [bool](-2..2) |??? 'match' : 'nomatch')

PowerShell中的三元运算符是在PowerShell version7.0中引入的。

[Condition] ? (output if True) : (output if False)

例01

$a = 5; $b = 6
($a -gt $b) ? "True" : "False"

输出

False

例子02

($a -gt $b) ? ("$a is greater than $b") : ("$a is less than $b")

输出

5 is less than 6

更多的信息 https://www.tutorialspoint.com/how-ternary-operator-in-powershell-works

$result = If ($condition) {"true"} Else {"false"}

为了在表达式中或作为表达式使用，而不仅仅是赋值，将它包装在$()中，这样:

write-host  $(If ($condition) {"true"} Else {"false"})