Powershell重写赋值和比较运算符
使用Powershell 5,您现在可以实现自定义类。随着时间的推移,您最终会希望开始重载操作符,以执行以下操作Powershell重写赋值和比较运算符,powershell,class,operator-overloading,powershell-5.0,Powershell,Class,Operator Overloading,Powershell 5.0,使用Powershell 5,您现在可以实现自定义类。随着时间的推移,您最终会希望开始重载操作符,以执行以下操作 class Number { [int] $value = 0 Number() {} # empty constructor Number ([int]$somethingElse) {$this.value = $somethingElse} } $one = [number]::new(1) $two = [number]::new
class Number
{
[int] $value = 0
Number() {} # empty constructor
Number ([int]$somethingElse)
{$this.value = $somethingElse}
}
$one = [number]::new(1)
$two = [number]::new(2)
$three = $one + $two
if ($three -eq ($one + $two))
{"3 = 1 + 2"}
else
{"3 <> 1 + 2 "}
类号
{
[int]$value=0
Number(){}#空构造函数
数字([int]$somethingElse)
{$this.value=$somethingElse}
}
$one=[number]::新的(1)
$two=[number]::新的(2)
$3=$1+$2
如果($3-相等($1+$2))
{"3 = 1 + 2"}
其他的
{"3 1 + 2 "}
但这似乎没有很好的文档记录,在搜索堆栈溢出后,我找不到如何执行此操作通常认为在powershell中无法执行此操作。不幸的是,在几次谷歌搜索和堆栈溢出搜索之后,我就要放弃了。但后来我发现了要点,结果证明你可以 考虑到这对我来说是多么难以发现,我想为其他人提供一个清晰且格式良好的例子(当我很快忘记如何做到这一点时,还有我未来的自己) 感谢JFFail发布到Github 您将需要适当地重载这些,它们应该是不言自明的,但请随意询问是否有问题
SetValue([int]$newValue)
GetValue()
[boolean] Equals($otherNumber)
[string] ToString() # you can get more advanced by overloading "IConvertible.ToType" but that's a whole can of worms all it's own
static [MyClass] op_Addition ([MyClass]$first, [MyClass]$second)
static [MyClass] op_Subtraction([MyClass]$first, [MyClass]$second)
static [MyClass] op_Multiply ([MyClass]$first, [MyClass]$second)
static [MyClass] op_Division ([MyClass]$first, [MyClass]$second)
对于-gt
和-lt
,您需要使用以下命令。注意:虽然这确实支持-eq
,但您可以使用如上所示的Equals(object)
来获得它,而这不需要继承自IComparable
class MyClass : System.IComparable
# requires inheritance from System.IComparable
[int] CompareTo($otherNumber)
# CANNOT declare type in parameter declaration, you'd have to check it later.
# 1 is greater than
# 0 is equal
# -1 is less than
# $null can be returned to indicate invalid comparison
这里有一个有效的例子
# If you don't need -lt or -gt then you don't have to inherit from System.IComparable
class Number : System.IComparable
{
[int] $value = 0
Number() {} # empty constructor
Number ([int]$somethingElse)
{$this.value = $somethingElse}
[void] SetValue ([int]$newValue)
{$this.value = $newValue}
[int] GetValue()
{return $this.value}
[boolean] Equals($otherNumber)
{
if ($this.value -eq $otherNumber.GetValue())
{return $true}
else
{return $false}
}
[int] CompareTo($otherNumber)
{
if ($this.value -gt $otherNumber.GetValue()) {return 1}
if ($this.value -eq $otherNumber.GetValue()) {return 0}
if ($this.value -lt $otherNumber.GetValue()) {return -1}
return $null
}
[string] ToString()
{return $this.value.ToString()}
static [Number] op_Addition ([Number]$first, [Number]$second)
{return [Number]::new($first.GetValue() + $second.GetValue())}
static [Number] op_Subtraction([Number]$first, [Number]$second)
{return [Number]::new($first.GetValue() - $second.GetValue())}
static [Number] op_Multiply([Number]$first, [Number]$second)
{return [Number]::new($first.GetValue() * $second.GetValue())}
static [Number] op_Division([Number]$first, [Number]$second)
{return [Number]::new($first.GetValue() / $second.GetValue())}
}
# Very Basic Unit Tests
$firstNumber = [Number]::new(8)
$secondNumber = [Number]::new(12)
$thirdNumber = [Number]::new(8)
if ($firstNumber -eq $secondNumber)
{Write-Output ("{0} == {1}" -F $firstNumber, $secondNumber)}
else
{Write-Output ("{0} <> {1}" -F $firstNumber, $secondNumber)}
if ($firstNumber -eq $thirdNumber)
{Write-Output ("{0} == {1}" -F $firstNumber, $thirdNumber)}
else
{Write-Output ("{0} <> {1}" -F $firstNumber, $thirdNumber)}
switch ($true)
{
($firstNumber -gt $secondNumber) {Write-Output ("{0} > {1}" -F $firstNumber, $secondNumber)}
($firstNumber -eq $secondNumber) {Write-Output ("{0} == {1}" -F $firstNumber, $secondNumber)}
($firstNumber -lt $secondNumber) {Write-Output ("{0} < {1}" -F $firstNumber, $secondNumber)}
}
$fourthNumber = $firstNumber + $secondNumber
Write-Output ("{0} = {1} + {2}" -F $fourthNumber, $firstNumber, $secondNumber)
$fifthNumber = $secondNumber - $thirdNumber
Write-Output ("{0} = {1} - {2}" -F $fifthNumber, $secondNumber, $thirdNumber)
$sixthNumber = $firstNumber * $secondNumber
Write-Output ("{0} = {1} * {2}" -F $sixthNumber, $firstNumber, $secondNumber)
$seventhNumber = $sixthNumber / $firstNumber
Write-Output ("{0} = {1} / {2}" -F $seventhNumber, $sixthNumber, $firstNumber)
#如果不需要-lt或-gt,则不必从System.IComparable继承
类别编号:System.IComparable
{
[int]$value=0
Number(){}#空构造函数
数字([int]$somethingElse)
{$this.value=$somethingElse}
[void]SetValue([int]$newValue)
{$this.value=$newValue}
[int]GetValue()
{返回$this.value}
[boolean]等于($otherNumber)
{
if($this.value-eq$otherNumber.GetValue())
{返回$true}
其他的
{返回$false}
}
[int]比较($otherNumber)
{
if($this.value-gt$otherNumber.GetValue()){return 1}
if($this.value-eq$otherNumber.GetValue()){return 0}
if($this.value-lt$otherNumber.GetValue()){return-1}
返回$null
}
[string]ToString()
{返回$this.value.ToString()}
静态[Number]运算加法([Number]$first,[Number]$second)
{return[Number]::new($first.GetValue()+$second.GetValue())}
静态[Number]运算减法([Number]$first,[Number]$second)
{return[Number]:new($first.GetValue()-$second.GetValue())}
静态[Number]运算乘法([Number]$first,[Number]$second)
{return[Number]::new($first.GetValue()*$second.GetValue())}
静态[Number]运算分割([Number]$first,[Number]$second)
{return[Number]::new($first.GetValue()/$second.GetValue())}
}
#非常基本的单元测试
$firstNumber=[Number]::新(8)
$secondNumber=[Number]::新(12)
$thirdNumber=[Number]::新(8)
if($firstNumber-eq$secondNumber)
{写入输出(“{0}=={1}”-F$firstNumber,$secondNumber)}
其他的
{写入输出(“{0}{1}”-F$firstNumber,$secondNumber)}
if($firstNumber-eq$thirdNumber)
{写入输出(“{0}=={1}”-F$firstNumber,$thirdNumber)}
其他的
{写入输出(“{0}{1}”-F$firstNumber,$thirdNumber)}
开关($true)
{
($firstNumber-gt$secondNumber){写入输出(“{0}>{1}”-F$firstNumber,$secondNumber)}
($firstNumber-eq$secondNumber){写入输出(“{0}==={1}”-F$firstNumber,$secondNumber)}
($firstNumber-lt$secondNumber){写入输出(“{0}<{1}”-F$firstNumber,$secondNumber)}
}
$fourthNumber=$firstNumber+$secondNumber
写入输出(“{0}={1}+{2}”-F$fourthNumber、$firstNumber、$secondNumber)
$fifthNumber=$secondNumber-$thirdNumber
写入输出(“{0}={1}-{2}”-F$fifthNumber、$secondNumber、$thirdNumber)
$sixthNumber=$firstNumber*$secondNumber
写入输出(“{0}={1}*{2}”-F$sixthNumber、$firstNumber、$secondNumber)
$seventhNumber=$sixthNumber/$firstNumber
写入输出(“{0}={1}/{2}”-F$seventhNumber、$sixthNumber、$firstNumber)
这是输出
> 8 <> 12
> 8 == 8
> 8 < 12
> 20 = 8 + 12
> 4 = 12 - 8
> 96 = 8 * 12
> 12 = 96 / 8
>8 12
> 8 == 8
> 8 < 12
> 20 = 8 + 12
> 4 = 12 - 8
> 96 = 8 * 12
> 12 = 96 / 8