使用ajax问题发送JSON数据

Question

I have the following code:

var arr = {City:'Moscow', Age:25};

$.ajax({
    url: "<? echo $this->createUrl('cities/index');?>",
    type: "POST",
    data: JSON.stringify(arr),
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    async: false,
    success: function(data){
        alert(data);
    }
});

The result is null. In the PHP side I have:

echo json_encode($_POST);

and

print_r($_POST);

But both are giving empty results (checked Firebug also).

Answer 1

I guess you don't need to stringyfy the data because data should be PlainObject or String but in your case you can simply write like below

var arr = {City:'Moscow', Age:25};

       $.ajax({
            url: "<? echo $this->createUrl('cities/index');?>",
            type: "POST",
            data: arr,
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            async: false,
            success: function(data){
                alert(data);
            }
        });

as documented in jquery official site https://api.jquery.com/jQuery.ajax/

data

Type: PlainObject or String

Data to be sent to the server. It is converted to a query string, if not already a string. It's appended to the url for GET-requests. See processData option to prevent this automatic processing. Object must be Key/Value pairs. If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting (described below).