data format of ajax request

ajax submit data type

1. The source of the problem

When using ajax today, I found that when getting data is passed, parameters cannot be passed when passing a json string, so I did some experiments to test the difference between ajax get and post data passing.

2. Concept

Ajax has three ways to pass data:

• json format
• json string format
• Standard parameter mode

1.json format

形如： 
{“username”:”chen”,”nickname”:”alien”}

ajax：

$.ajax({
    type:"post",
    url:"/test/saveUser",
    data:{"username":"chen","nickname":"alien"}, dataType:"json", success: function(data){ console.log(data); } });

 

2. The json string 
is like: 
"{"username":"chen","nickname":"alien"}" or JSON.stringify({"username":"chen","nickname":"alien"})

ajax：

$.ajax({
    type:"post", url:"/test/saveUser", data:JSON.stringify({"username":"chen","nickname":"alien"}), contentType:"json/application" dataType:"json", success: function(data){ console.log(data); } });

The get request parameters in this format cannot be passed, the json string will not be parsed into parameters 
and contentType: "json/application" needs to be added

3. Standard parameter mode

形如： 
“username=chen&nickname=alien”

ajax：

$.ajax({
    type:"post", url:"/test/saveUser", data:"username=chen&nickname=alien", dataType:"json", success: function(data){ console.log(data); } });

$(“#form1”).serialize() is to spell the data of the form into a string in this format!

3. Summary

The post request can pass parameters in types 1, 2,  and 3. The
get request can pass parameters in types 1 
and 3. $(“#form1”).serialize() is to assemble the name and value of the input in the corresponding form, and finally form 3 types of strings