将 json 对象添加到空 json 数组（powershell）答案

【问题标题】：Add json object to empty json array (powershell)将 json 对象添加到空 json 数组（powershell）
【发布时间】：2020-09-25 04:18:02
【问题描述】：

我有以下 ps/json:

$a = '[{"Type":"1","Name":"A"},{"Type":"2","Name":"B"}]'
$ps = $a | ConvertFrom-Json
Type Name
---- ----
1    A
2    B

#Now, I want to add this array into another array, so the resulting json should look like this:
[[{"Type":"1","Name":"A"},{"Type":"2","Name":"B"}]]

Remove-TypeData System.Array #needed for workaround for powershell bug: https://stackoverflow.com/questions/20848507/why-does-powershell-give-different-result-in-one-liner-than-two-liner-when-conve/38212718#38212718

$w = @()
$w += , $ps
$w |ConvertTo-Json
[
    {
        "Type":  "1",
        "Name":  "A"
    },
    {
        "Type":  "2",
        "Name":  "B"
    }
]


#It's apparent that the $ps object was NOT added to an empty array as desired, however when multiple instances are added ($w += , $ps twice for example) it works as expected:

[
    [
        {
            "Type":  "1",
            "Name":  "A"
        },
        {
            "Type":  "2",
            "Name":  "B"
        }
    ],
    [
        {
            "Type":  "1",
            "Name":  "A"
        },
        {
            "Type":  "2",
            "Name":  "B"
        }
    ]
]

所以看起来数组在那里但是外部括号没有被返回（因为它们应该是）

我已经阅读了其他问题，但找不到解决方案，如果有人能够分享？

【问题讨论】：

标签： json powershell

【解决方案1】：

为避免混淆，在这种情况下最好避免使用管道（其中数组总是枚举）：

$ps = '[{"Type":"1","Name":"A"},{"Type":"2","Name":"B"}]' | ConvertFrom-Json

# Wrap $ps in a single-element array.
$w = , $ps

# Workaround for Windows PowerShell:
# See https://stackoverflow.com/a/38212718/45375
Remove-TypeData -ErrorAction Ignore System.Array

# Pass the wrapper array via -InputObject to prevent enumeration.
ConvertTo-Json -InputObject $w -Compress

以上产出：

[[{"Type":"1","Name":"A"},{"Type":"2","Name":"B"}]]

【讨论】：