JSFiddle - React, Tailwind, and code Playground
demonstrating nested-loop speeds
by jonchius
HTML
<div id="display1"></div>
<div id="display2"></div>
<div id="count"></div>
JavaScript
withoutLoop(200);
withLoop(200);
// without nested loop
function withoutLoop(iterations) {
$("#count").append("<h1>without nested loop</h1>");
var start1 = Date.now();
$("#count").append("<p>began: " + start1 + "</p>");
for (var i=0; i<iterations*iterations; i++) {
$("#display1").html((i+1));
}
var end1 = Date.now();
$("#count").append("<p>ended: " + end1 + "</p>");
$("#count").append("<p>This took <strong>" + (end1-start1) + "</strong> milliseconds</p>");
}
// with nested loop
function withLoop(iterations) {
$("#count").append("<h1>with nested loop</h1>");
var start2 = Date.now();
$("#count").append("<p>began: " + start2 + "</p>");
for (var i=0; i<iterations; i++) {
for (var j=0; j<iterations; j++) {
$("#display2").html((i+1));
}
}
var end2 = Date.now();
$("#count").append("<p>ended: " + end2 + "</p>");
$("#count").append("<p>This took <strong>" + (end2-start2) + "</strong> milliseconds</p>");
}