JSFiddle - React, Tailwind, and code Playground
HTML
<input value="50855">
<button>Time</button>
JavaScript
var n = 50855;
$('input').change(function(){
n = +this.value;
});
$('button').click(function(){
var start = +new Date, a = [];
for(var i = 0; i < n; i++)
a[i] = i;
for(var i = 0; i < a.length; i++)
a.splice(i--, 1);
$('body').append('<p>' + (+new Date - start));
});