Different examples of ajax versus post handling json in jQuery

Recently, when I was making user comments on the portal, I didn't use jquery for a long time. However, I didn't think that the post method was used to handle the json data of ajax callback. Unexpectedly, such a small problem hung for me for several hours, and then I was able to handle it with the ajax method, and I found that the original post method callback json must be eval, and the ajax method did the default processing. Please be careful.

function haha() {
jQuery.post("addComment!comment.action",
function aa(data) {
data = eval(data);//POST method must be added, the ajax method handles it automatically
alert(data[0].userId);
alert(data[0].userName);
},
"json"
);

jQuery.ajax({
type:"post",
url:"addComment!comment.action",
dataType:"json",
success: function aa(data) {
alert(data[0].userId);
alert(data[0].userName);
}
});
}

Background:

public String comment() {

try{

User u = new User("user", "koko");

list = new ArrayList<User>();

list.add(u);

//map.put("id", userId);

// JSONObject jb = JSONObject.fromObject(list); // name:"+userName +",

// info = jb.toString();

System.out.println(list);

}

catch (Exception e) {

e.printStackTrace();

}

return SUCCESS;

}

Configuration:

<package name="ajax" extends="json-default">

<action name="addComment" class="org.test.action.CommentAction">

<result type="json">

<param name="root">list</param>

</result>

</action>