JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="testInput" value="old 1"/>
<input type="text" id="testInput2" value="old 2"/>
<input type="text" id="testInput3" value="old 3"/>
<input type="text" id="testInput4" value="old 4"/>
<input type="hidden" id="haschanged" value=""/>

JavaScript

$(document).ready();{
var oldValue=[];
$('input').each(function(){
    oldValue.push($(this).val());
})
}