JSFiddle - React, Tailwind, and code Playground

JavaScript

var isInteger1 = function(a) {
	return ((typeof a !== 'number') || (a % 1 !== 0)) ? false : true;
};

var isInteger2 = function(possibleInteger) {
	return Object.prototype.toString.call(possibleInteger) !== "[object Array]" && /^[\d]+$/.test(possibleInteger);
}



var loadTest = function(fn, value) {
	var start = new Date;
	for(var i=0; i<1000000; i++) {
		fn(value);
	}
	return new Date - start;
};


var compare = function(testValues, i) {
	var value = testValues[i];
	var time1 = loadTest(isInteger1, value);
	var time2 = loadTest(isInteger2, value);
	
	$('body').append('<p>'+value+' => '+time1+'ms vs '+time2+'ms</p>');
	
	if(i < testValues.length-1) {
		setTimeout(function() {
			compare(testValues, i+1);
		}, 10);
	}
};

var testValues = [1, 1.1, '1', [1], {foo:'bar'}];

compare(testValues, -1);