JSON Encode/Decode

JSON handling for APIs: encoding, decoding, and error checks.

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Encoding Arrays to JSON

json_encode converts arrays/objects into JSON strings. This is the basis for API responses.

<?php
$data = [
  'ok' => true,
  'items' => [
    ['id' => 1, 'title' => 'PHP Intro'],
    ['id' => 2, 'title' => 'Arrays'],
  ],
];

echo json_encode($data);

Pretty Print (Development)

Pretty JSON is easier to read while developing. For production, compact JSON is usually fine.

<?php
echo json_encode($data, JSON_PRETTY_PRINT);

Decoding JSON to Arrays

json_decode can return an object or an associative array. For typical backend code, associative arrays are often easier to work with.

<?php
$raw = '{"id":1,"name":"Ozan"}';

$decoded = json_decode($raw, true); // true => associative array
echo $decoded['name'];

Handling JSON Errors

Invalid JSON returns null. Always check json_last_error or use the JSON_THROW_ON_ERROR flag to avoid silent failures.

<?php
try {
  $payload = json_decode($raw, true, 512, JSON_THROW_ON_ERROR);
} catch (JsonException $e) {
  echo 'Invalid JSON';
}

Returning JSON Responses

For APIs, set the correct content type and return JSON. Never echo raw errors in production.

<?php
header('Content-Type: application/json; charset=utf-8');

echo json_encode([
  'ok' => true,
  'message' => 'Hello',
]);

Production Tip

Validate decoded payloads (required keys, types) before using them. JSON decode gives you “some data”, not “trusted data”. Validation belongs on the server.

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