PHP 返回 Json 函数：json_encode()

<?php
header('Content-type: text/json');

$fruits = array (
    "fruits"  => array("a" => "orange", "b" => "banana", "c" => "apple"),
    "numbers" => array(1, 2, 3, 4, 5, 6),
    "holes"   => array("first", 5 => "second", "third")
);
echo json_encode($fruits);
?>