PowerShell 技能连载 - 比较字符串列表

在前一个例子中我们使用 HashSet 来对比数字列表，并查找哪些元素在两个列表中都出现，或只在一个列表中出现。

字符串列表也可以做相同的事。假设您有两个名字清单，并且希望知道哪些名字在两个名单中都出现，或只在一个名单中出现，请试试以下代码：

$set1 = New-Object System.Collections.Generic.HashSet[string] (,[string[]]@('Harry','Mary','Terri'))
$set2 = New-Object System.Collections.Generic.HashSet[string] (,[string[]]@('Tom','Tim','Terri','Tobias'))

"Original Sets:"
"$set1"
"$set2"

# in both
$copy = New-Object System.Collections.Generic.HashSet[string] $set1
$copy.IntersectWith($set2)
"In Both"
"$copy"

# combine
$copy = New-Object System.Collections.Generic.HashSet[string] $set1
$copy.UnionWith($set2)
"All Combined"
"$copy"

# exclusive
$copy = New-Object System.Collections.Generic.HashSet[string] $set1
$copy.ExceptWith($set2)
"Exclusive in Set 1"
"$copy"

# exclusive either side
$copy = New-Object System.Collections.Generic.HashSet[string] $set1
$copy.SymmetricExceptWith($set2)
"Exclusive in both (no duplicates)"
"$copy"

以下是执行结果：

Original Sets:
Harry Mary Terri
Tom Tim Terri Tobias
In Both
Terri
All Combined
Harry Mary Terri Tom Tim Tobias
Exclusive in Set 1
Harry Mary
Exclusive in both (no duplicates)
Harry Mary Tobias Tom Tim