JSFiddle - React, Tailwind, and code Playground

HTML

<p>var a = [0, 0, 2], b = a;</p>
<p id="out1" class="out"></p>

<p>var a = [0, 0, 2], b = [0, 0, 2];</p>
<p id="out2" class="out"></p>

CSS

.out {
    background: #dddddd;
    border: 1px solid #cccccc;
    padding: .5em;
}

JavaScript

function printRelation(a, b, out) {
    var text;
    if (a === b) {
        text = "a === b";
    } else if (a == b) {
        text = "a == b";
    } else {
        text = "a != b";
    }
    $('#' + out).text(text);
}

var a = [0, 0, 2], b = a;
printRelation(a, b, 'out1');
a = [0, 0, 2];
b = [0, 0, 2];
printRelation(a, b, 'out2');