如何将数据从Javascript传递到PHP，反之亦然？

Question

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

Answer 1

从PHP传递数据很容易，您可以使用它生成JavaScript。另一种方法要难一些-您必须通过Javascript请求来调用PHP脚本。

一个示例（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.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 -->

不管get_data.php产生什么，它将出现在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；）