Return JSON from a PHP script

<?php
    // set header
    header('Content-Type: application/json'); 

    // create a php array
    $myarr = [
        [ "id" => 1, "name" => "Math" ],
        [ "id" => 1, "name" => "physics" ],
        [ "id" => 1, "name" => "Chemistry" ]
    ];

    // convert to json and print
    echo json_encode($myarr);
?>