为什么数组不会通过ajax调用发送？

Question

In my ajax code I'm sending an associative array to the go lang api but go lang would not receiving any array. Why?

for (var i = 1; i <= optionsArr; i++) {
    span_arr.push({
        day       : valueSelected,
        time_slug : i,
        timing    : $("#"+i).text(),
        count     : $('#select_count'+i).val()
    });
}
console.log(span_arr[1].time_slug);
$.ajax({
    url:"/api/v1/provider_spot",
    type:"POST",
    data:{span_arr:span_arr},
    dataType:"json",
    success:function(response){
        console.log(response);
    }
});

Why this ajax will not sending the array to the go api? Here in go lang following mvc structure I want to receiving this data:

 Route{"SaveProviderSpot", "POST", "/provider_spot", controller.SaveProviderSpot},

 func SaveProviderSpot(c *gin.Context) {
   fmt.Println(c.PostForm("span_arr"))
 }

Answer 1

You can not send an array directly from client to server,due to the array definition may not be the same in both sides.

Two ways to solve it:

a. You can convert the array into a json string in the clinet,then send it to server as a string parameter,in the server side,you can parse it and convert it to array

b. Iterate the array,and convert it to a string using some special characters,also pass to server as string parameter,an example is as below:

var dataStr = "";
for (var i = 1; i <= optionsArr; i++) {
    //each array element split with 3 semicolons,and each property in element split with 2 semicolons
    dataStr += valueSelected + ";;" + i + ";;" + $("#"+i).text() 
           + ";;" + $('#select_count'+i).val() + ";;;";
}
$.ajax({
    url:"/api/v1/provider_spot",
    type:"POST",
    data:{dataStr:dataStr},
    dataType:"json",
    success:function(response){
        console.log(response);
    }
});
//now it is correct