I am a newbie to Powershell and I couldn't find this on googling but how do I build a json structure with an array inside? Is it through a custom object? Have been a bit confused by the syntax that I have seen online and not sure what is the recommended way to do it. Eventually I need to be able to save it to a JSON file too.
json_ret = {
"a": 4,
"b": [ {"c" : 5, "d": "text", "e": "foo"}]
}
Yes you can build a json object through a PSCustomObject:
[PSCustomObject]@{
a = 4
b = @([ordered]@{
c = 5
d = "text"
e = "foo"
})
} | ConvertTo-Json
First we create PSObject using its type accelerator PSCustomObject.
Then we define the root key and value "a", and we have to create an array inside "b".
The @() statement creates an array, but we can't we create key-value pairs in array. So we use @{} to create hashtable. Before it [ordered] flag says the hashtable to keep the exact structure as we have created it.
Then we define the array values, and after that close the internal array-hashtable.
Now we end the PSCustomObject and pipe it ConvertTo-Json. Now you get a converted json.
Footnotes
[PSCustomObject]@{
a = 4
b = @([ordered]@{
c = 5
d = "text"
e = "foo"
})
} | ConvertTo-Json | Out-File "Filepath"
$variable = ([PSCustomObject]@{
a = 4
b = @([ordered]@{
c = 5
d = "text"
e = "foo"
})
} | ConvertTo-Json)
If you want to create the JSON document directly, as a string, it's simplest to use a verbatim here-string:
$json_ret = @'
{
"a": 4,
"b": [ {"c" : 5, "d": "text", "e": "foo"}]
}
'@
You can easily save that to a file with $json_ret | Set-Content file.json, for instance.
By contrast, if you want to construct your data as an object graph first, to be converted to JSON with ConvertTo-Json later, see Wasif_Hasan's helpful answer.
As for what you tried:
An unquoted { ... } construct is a script block, which is a piece of PowerShell code for later invocation on demand - and the contents of your JSON document happen not to constitute valid PowerShell code, causing construction of the script block to fail.
If using variables, then can create body including array like shown below, where $text is the variable. No need to user ConvertTo-Json and can easily copy the body from postman directly.
$text = "ABC"
# Post Body
$body = @"
{
"name" = "$text",
"description" = "$text",
"myArray": [
{
"id": "2c91808680d3c34b0180dc81d78c21e9",
"type": "myType",
"name": "myName"
}
]
}
"@
$body
