Returning JSON from a PHP script

The Problem

How can I return JSON from a PHP script?

The Solution

We use the header() function to set Content-Type to application/json. Then we can use the json_encode() function to covert our PHP array into a JSON-formatted string. For example:

<?php
// Set the header content-type
header('Content-Type: application/json');

// Create or get a PHP array (or object)
$array = [
    'Canada' => 'Ottawa',
    'India' => 'New Delhi',
    'United States' => 'Washington, D.C.',
    'France' => 'Paris',
];

// Encode to JSON format
$json = json_encode($array, JSON_PRETTY_PRINT);

// Display
echo $json;

As a second argument, we use JSON_PRETTY_PRINT to add spaces to improve the readability of the output. For example:

{
    "Canada": "Ottawa",
    "India": "New Delhi",
    "United States": "Washington, D.C.",
    "France": "Paris"
}

While it’s not essential to set the header content type to application/json, it’s recommended as a best practice. Especially when you’re working with APIs and various services, explicitly communicating to the client that the response will be in JSON format ensures the data is correctly handled and processed.