Read, Modify, and Parse JSON File (Object) with PowerShell

JSON is a popular text-based format for representing and transmitting structured data based on JavaScript object syntax. There are two cmdlets in PowerShell that allow you to work with the JSON data format: ConvertFrom-Json and ConvertTo-Json. Let’s look at how you can use PowerShell to create, read, or modify JSON objects and save them to files.

Data in JSON format is represented as key:value pairs (property nesting is allowed). Suppose you want to write JSON data to a file. Create a JSON structured data object:

$obj = @{
    Name = "Henry"
    Roles = @{
          AD = "Admin"
          SQL = "Report"
      }
      "Company" = "woshub"
  }

Now convert the object to JSON format and save it to a file with a .json extension:

$json = $obj | ConvertTo-Json
$json | Set-Content -Path C:\PS\userroles.json

You can now read the JSON file:

$json = Get-Content -Path C:\PS\userroles.json -Raw | ConvertFrom-Json

List all JSON object properties:

$json|fl

Or you can get the value of a particular property in a JSON object:

$json.roles.sql

Use the Add-Member command to add a new property to a JSON object:

$json| Add-Member -MemberType NoteProperty -Name "Email" -Value "henry@woshub.com"

Use the following commands to change a single value in a JSON object and save it to a file:

$json.roles.sql='Admin'
$json|ConvertTo-Json| Set-Content -Path C:\PS\userroles.json

Remove JSON object property:

$json.PSObject.Properties.Remove("Email")

By using the Invoke-WebRequest PowerShell cmdlet, you can access the JSON HTTP API to get data from external web services (sites). For example, to list A records returned by Google’s DNS service in JSON format:

$site="woshub.com"
$rawresp=Invoke-WebRequest "https://dns.google/resolve?name=$site&type=A"
$rawjson = ConvertFrom-Json -InputObject $rawresp.Content
$rawjson.answer.data