数组上的组对象？

Question

如何在下列数组的前两列（a，b）和（c，e）上使用Group-Object？

$a = @('a','b','x',10), 
@('a','b','y',20), 
@('c','e','x',50), 
@('c','e','y',30) 

Answer 1

Group-Object接受匿名计算性能，代替属性名称：

PS C:\> $a | Group-Object @{ Expression={$_[0]} },@{ Expression = {$_[1]} } 

它还接受一个脚本块：

PS C:\> $a | Group-Object {$_[0]},{$_[1]} 

只要表达可以评价为字符串：

PS C:\> Get-Help Group-Object -Parameter Property 

-Property [<Object[]>] 
    Specifies the properties for grouping. The objects are arranged into groups 
    based on the value of the specified property. 

    The value of the Property parameter can be a new calculated property. 
    To create a calculated, property, create a hash table with an Expression key 
    that specifies a string or script block value.