如何将数据从Javascript传递到PHP,反之亦然？

如何通过Javascript脚本请求PHP页面并将数据传递给它？然后我如何让PHP脚本将数据传递回Javascript脚本？

client.js：

data = {tohex: 4919, sum: [1, 3, 5]};
// how would this script pass data to server.PHP and access the response?

server.PHP：

$tohex = ... ; // How would this be set to data.tohex?
$sum = ...; // How would this be set to data.sum?
// How would this be sent to client.js?
array(base_convert($tohex, 16), array_sum($sum))

解决方法:

从PHP传递数据很简单,您可以使用它生成JavaScript.另一种方式有点难 – 你必须通过Javascript请求调用PHP脚本.

一个例子(为简单起见,使用传统的事件注册模型)：

<!-- headers etc. omitted -->
<script>
function callPHP(params) {
    var httpc = new XMLHttpRequest(); // simplified for clarity
    var url = "get_data.PHP";
    httpc.open("POST", url, true); // sending as POST

    httpc.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    httpc.setRequestHeader("Content-Length", params.length); // POST request MUST have a Content-Length header (as per HTTP/1.1)

    httpc.onreadystatechange = function() { //Call a function when the state changes.
        if(httpc.readyState == 4 && httpc.status == 200) { // complete and no errors
            alert(httpc.responseText); // some processing here, or whatever you want to do with the response
        }
    };
    httpc.send(params);
}
</script>
<a href="#" onclick="callPHP('lorem=ipsum&foo=bar')">call PHP script</a>
<!-- rest of document omitted -->

无论get_data.PHP产生什么,它都会出现在httpc.responseText中.错误处理,事件注册和跨浏览器XMLHttpRequest兼容性留给读者简单的练习;)