<?php
$data = /** whatever you're serializing **/;
header("Content-type: application/json; charset=utf-8");
echo json_encode($data);
?>

如果你想要js对象，使用头content-type:

<?php
$data = /** whatever you're serializing **/;
header('Content-Type: application/json; charset=utf-8');
echo json_encode($data);

如果你只想要json: remove header content-type属性，只需要encode和echo。

<?php
$data = /** whatever you're serializing **/;
echo json_encode($data);

<?php
$data = /** whatever you're serializing **/;
header("Content-type: application/json; charset=utf-8");
echo json_encode($data);
?>

一个返回带有HTTP状态代码的JSON响应的简单函数。

function json_response($data=null, $httpStatus=200)
{
    header_remove();

    header("Content-Type: application/json");

    http_response_code($httpStatus);

    echo json_encode($data);

    exit();
}

如果你查询一个数据库，需要JSON格式的结果集，可以这样做:

<?php

$db = mysqli_connect("localhost","root","","mylogs");
//MSG
$query = "SELECT * FROM logs LIMIT 20";
$result = mysqli_query($db, $query);
//Add all records to an array
$rows = array();
while($row = $result->fetch_array()){
    $rows[] = $row;
}
//Return result to jTable
$qryResult = array();
$qryResult['logs'] = $rows;
echo json_encode($qryResult);

mysqli_close($db);

?>

有关使用jQuery解析结果的帮助，请参阅本教程。

设置访问安全性也很好——只需将*替换为您希望能够访问它的域。

<?php
header('Access-Control-Allow-Origin: *');
header('Content-type: application/json');
    $response = array();
    $response[0] = array(
        'id' => '1',
        'value1'=> 'value1',
        'value2'=> 'value2'
    );

echo json_encode($response); 
?>

这里有更多的例子:如何绕过Access-Control-Allow-Origin?