JSON in PHP

json_encode

Function json_encode turns an array into a JSON string. Keys become JSON names and values keep their types.

Use it whenever PHP must send structured data to another system.

$data = ["name" => "Ada", "score" => 42]; echo json_encode($data);

json_decode to array

Function json_decode turns a JSON string back into PHP data. Pass true as second argument to get an array instead of an object.

Read the reference json_decode for nested examples.

$json = "{\"name\":\"Ada\",\"score\":42}"; $result = json_decode($json, true); echo $result["name"]; var_dump($result);

json_last_error

Invalid JSON returns null, so always check the error state.

Function json_last_error returns a code and json_last_error_msg explains it. Validate input early to keep failures easy to locate.

$bad = "{broken}"; json_decode($bad); echo json_last_error(); echo json_last_error_msg();

Build a tiny JSON response

Set the JSON content header before any output. Encode a small array with status and data keys.

The browser or client receives one clean JSON document.

header("Content-Type: application/json"); $data = ["status" => "ok", "count" => 2]; echo json_encode($data);

Next: Reading and writing files

Article author: Arthur Isaev