JSON operations (ConvertFrom-Json, ConvertTo-Json) in PowerShell

Introduction

JSON operations let you easily change data between text and objects. This helps scripts talk with web services or save data in a simple format.

When you get data from a web API and want to use it in your script.

When you want to save script data in a file that other programs can read.

When you need to send data from your script to another program or service.

When you want to read a JSON file and work with its data inside PowerShell.

When you want to convert PowerShell objects to JSON text for sharing or storage.

Syntax

PowerShell

ConvertFrom-Json [-InputObject] <string> [<CommonParameters>]
ConvertTo-Json [-InputObject] <psobject> [-Depth <int>] [<CommonParameters>]

ConvertFrom-Json turns JSON text into PowerShell objects you can work with.

ConvertTo-Json turns PowerShell objects into JSON text you can save or send.

Examples

This converts JSON text to an object, then prints the name property.

PowerShell

$jsonText = '{"name":"Alice","age":30}'
$obj = $jsonText | ConvertFrom-Json
$obj.name

This converts a PowerShell object to JSON text and prints it.

PowerShell

$obj = @{name='Bob'; age=25}
$jsonText = $obj | ConvertTo-Json
$jsonText

This converts a JSON array to objects and prints the first item's name.

PowerShell

$jsonText = '[{"item":"apple","qty":5},{"item":"banana","qty":3}]'
$list = $jsonText | ConvertFrom-Json
$list[0].item

Sample Program

This script shows how to convert JSON text to an object, read and change data, then convert it back to JSON text.

PowerShell

$jsonString = '{"city":"Paris","temperature":18}'
# Convert JSON text to object
$weather = $jsonString | ConvertFrom-Json

# Access properties
Write-Output "City: $($weather.city)"
Write-Output "Temperature: $($weather.temperature)°C"

# Change temperature
$weather.temperature = 20

# Convert back to JSON text
$newJson = $weather | ConvertTo-Json
Write-Output $newJson

Important Notes

Use the -Depth parameter with ConvertTo-Json if your object has nested objects deeper than 2 levels.

ConvertFrom-Json only works with valid JSON text. Invalid JSON will cause errors.

JSON keys become object properties you can access with dot notation.

Summary

ConvertFrom-Json changes JSON text into PowerShell objects.

ConvertTo-Json changes PowerShell objects into JSON text.

These commands help scripts work with data from web APIs or files easily.