JavaScript function for comparing performance of multiple functions. Pass in an object in this format {name: functionName, ...}

perfTest.js

function perf(fo) {
	var results = [];
	// perform test
	for(key in fo) {
		var f = fo[key];
		var start = new Date().getTime();
		for(var j=0;j<10000;j++) {
			f();
		}
		var end = new Date().getTime();
		// get the operations per second
		results[key] = {ops: Math.round(10000/((end-start)/1000))};
	}
	
	var fastest = 0;
	var slowest = 0;
	// find fastest and slowest
	for(key in results) {
		if(fastest < results[key].ops) {
			fastest = results[key].ops;
		}
		if(slowest == 0 || slowest > results[key].ops){
			slowest = results[key].ops
		}
	}
	
	// display results
	for(key in results) {
		var metrics;
		if(results[key].ops == fastest) {
			metrics = "fastest";
		} else {
			metrics = ((fastest - results[key].ops)/fastest)*100+'%';
			if(results[key].ops == slowest){
				metrics+=" slowest";
			} else {
				metrics+=" slower";
			}
		}	
		console.log(key+":"+results[key].ops+ "/ops "+metrics);
	}
}