File appending: emulating a database

Question

JavaScript

Morning. I'm wondering if my theory on file appending proves well for Offline User Logins.
I have the basic idea... pseudo-real code here

var inputs = document.querySelector("form");
var text = input.text;
var FR = new FileReader();
var TF = FR.read("stuff.txt");
if (FR.read("stuff.txt", "user") == text && FR.read("stuff.txt", "pass") == text) {
//blah
}
else {
//bwahahaha Incorrect.
}

Would doing this (reading or appending to a separate hidden file) be useful and work as intended?

Answer 1

Maybe you can find a solution helping with
https://stackoverflow.com/questions/26417772/reading-from-text-file-javascript