problem description

there is no way to dynamically change the value of success in the returned data

the environmental background of the problems and what methods you have tried

I use ajax as a login interface. Because there is no background, I use easymock to write fake data, but I find that the success in the data returned by ajax is always a fixed value. Cannot change dynamically as in php

<div id="wrapper">
    <h1 id="title"></h1>
    <div id="content">
        <label for="username"></label>
        <input type="text" id="username" value>
        <br/>
        <label for="pass"></label>
        <input type="password" id="pass" value>
    </div>
    <div id="btn">
        <button id="login"></button>
        <a href="-sharp"></a>
    </div>
</div>

var username=document.getElementById ("username"). Value;
var pass=document.getElementById ("pass"). Value;
var btn=document.getElementById ("login");
var xhr;
btn.onclick=function () {

if(window.XMLHttpRequest){
    xhr=new XMLHttpRequest();
}
else{
    xhr=new ActiveXObject("Microsoft.XMLHttpRequest");
}
xhr.open("get","https://easy-mock.com/mock/5b57d2a603a5844b1c942098/user/query?name="+username+"&pass="+pass,true);
xhr.send();
xhr.onreadystatechange=function () {
    if(xhr.readyState==4){
        if(xhr.status==200){
            console.log("");
            var data=JSON.parse(xhr.responseText);
            console.log(data);
            if(data.success){
                window.location.href="indexJS.html"
            }
            else{
                alert("");
            }
        }
    }
}

}

easymock data

what result do you expect? What is the error message actually seen?

I want to be able to determine whether the filled data exists in the simulation data, and if so, let the success in the returned data be true