jridgewell/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<title>String startsWith another string #jsbench #jsperf</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
</head>
<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
</body>
</html>

## suite.js
"use strict";

(function (factory) {
	if (typeof Benchmark !== "undefined") {
		factory(Benchmark);
	} else {
		factory(require("benchmark"));
	}
})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
		function startsWith(str, prefix) {
		    return str.startsWith(prefix);
		}

		function lastIndexOf(str, prefix) {
		    return str.length >= prefix.length && str.lastIndexOf(prefix, 0) === 0;
		}

		function slice(str, prefix) {
		    const length = prefix.length;
		    return str.length >= length && str.slice(0, length) === prefix;
		}

		function sliceWithoutIndex(str, prefix) {
		    return str.slice(0, prefix.length) === prefix;
		}
	};


	suite.add("String does start with, startsWith", function () {
		// String does start with, startsWith
		const string = 'testing#lit#';
		const prefix = '#lit#'
		startsWith(string, prefix);
	});

	suite.add("String does start with, lastIndexOf", function () {
		// String does start with, lastIndexOf
		const string = 'testing#lit#';
		const prefix = '#lit#'
		lastIndexOf(string, prefix);
	});

	suite.add("String does start with, slice", function () {
		// String does start with, slice
		const string = 'testing#lit#';
		const prefix = '#lit#'
		slice(string, prefix);
	});

	suite.add("String does start with, sliceWithoutIndex", function () {
		// String does start with, slice without index check
		const string = 'testing#lit#';
		const prefix = '#lit#'
		sliceWithoutIndex(string, prefix);
	});

	suite.add("String doesn't start with, startsWith", function () {
		// String doesn't start with, startsWith
		const string = 'testing#lit#';
		const prefix = 'other'
		startsWith(string, prefix);
	});

	suite.add("String doesn't start with, lastIndexOf", function () {
		// String doesn't start with, lastIndexOf
		const string = 'testing#lit#';
		const prefix = 'other'
		lastIndexOf(string, prefix);
	});

	suite.add("String doesn't start with, slice", function () {
		// String doesn't start with, slice
		const string = 'testing#lit#';
		const prefix = 'other'
		slice(string, prefix);
	});

	suite.add("String doesn't start with, sliceWithoutIndex", function () {
		// String doesn't start with, slice without index check
		const string = 'testing#lit#';
		const prefix = 'other'
		sliceWithoutIndex(string, prefix);
	});

	suite.add("Suffix longer than string, startsWith", function () {
		// Suffix longer than string, startsWith
		const string = '#lit#';
		const prefix = 'testingother'
		startsWith(string, prefix);
	});

	suite.add("Suffix longer than string, lastIndexOf", function () {
		// Suffix longer than string, lastIndexOf
		const string = '#lit#';
		const prefix = 'testingother'
		lastIndexOf(string, prefix);
	});

	suite.add("Suffix longer than string, slice", function () {
		// Suffix longer than string, slice
		const string = '#lit#';
		const prefix = 'testingother'
		slice(string, prefix);
	});

	suite.add("Suffix longer than string, sliceWithoutIndex", function () {
		// Suffix longer than string, slice without index check
		const string = '#lit#';
		const prefix = 'testingother'
		sliceWithoutIndex(string, prefix);
	});

	suite.on("cycle", function (evt) {
		console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
		console.log(new Array(30).join("-"));

		var results = evt.currentTarget.sort(function (a, b) {
			return b.hz - a.hz;
		});

		results.forEach(function (item) {
			console.log((idx + 1) + ". " + item);
		});
	});

	console.log("String startsWith another string #jsbench #jsperf");
	console.log(new Array(30).join("-"));
	suite.run();
});
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<title>String startsWith another string #jsbench #jsperf</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
	</head>
	<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
	</body>
	</html>
	"use strict";

	(function (factory) {
	if (typeof Benchmark !== "undefined") {
	factory(Benchmark);
	} else {
	factory(require("benchmark"));
	}
	})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
	function startsWith(str, prefix) {
	return str.startsWith(prefix);
	}

	function lastIndexOf(str, prefix) {
	return str.length >= prefix.length && str.lastIndexOf(prefix, 0) === 0;
	}

	function slice(str, prefix) {
	const length = prefix.length;
	return str.length >= length && str.slice(0, length) === prefix;
	}

	function sliceWithoutIndex(str, prefix) {
	return str.slice(0, prefix.length) === prefix;
	}
	};


	suite.add("String does start with, startsWith", function () {
	// String does start with, startsWith
	const string = 'testing#lit#';
	const prefix = '#lit#'
	startsWith(string, prefix);
	});

	suite.add("String does start with, lastIndexOf", function () {
	// String does start with, lastIndexOf
	const string = 'testing#lit#';
	const prefix = '#lit#'
	lastIndexOf(string, prefix);
	});

	suite.add("String does start with, slice", function () {
	// String does start with, slice
	const string = 'testing#lit#';
	const prefix = '#lit#'
	slice(string, prefix);
	});

	suite.add("String does start with, sliceWithoutIndex", function () {
	// String does start with, slice without index check
	const string = 'testing#lit#';
	const prefix = '#lit#'
	sliceWithoutIndex(string, prefix);
	});

	suite.add("String doesn't start with, startsWith", function () {
	// String doesn't start with, startsWith
	const string = 'testing#lit#';
	const prefix = 'other'
	startsWith(string, prefix);
	});

	suite.add("String doesn't start with, lastIndexOf", function () {
	// String doesn't start with, lastIndexOf
	const string = 'testing#lit#';
	const prefix = 'other'
	lastIndexOf(string, prefix);
	});

	suite.add("String doesn't start with, slice", function () {
	// String doesn't start with, slice
	const string = 'testing#lit#';
	const prefix = 'other'
	slice(string, prefix);
	});

	suite.add("String doesn't start with, sliceWithoutIndex", function () {
	// String doesn't start with, slice without index check
	const string = 'testing#lit#';
	const prefix = 'other'
	sliceWithoutIndex(string, prefix);
	});

	suite.add("Suffix longer than string, startsWith", function () {
	// Suffix longer than string, startsWith
	const string = '#lit#';
	const prefix = 'testingother'
	startsWith(string, prefix);
	});

	suite.add("Suffix longer than string, lastIndexOf", function () {
	// Suffix longer than string, lastIndexOf
	const string = '#lit#';
	const prefix = 'testingother'
	lastIndexOf(string, prefix);
	});

	suite.add("Suffix longer than string, slice", function () {
	// Suffix longer than string, slice
	const string = '#lit#';
	const prefix = 'testingother'
	slice(string, prefix);
	});

	suite.add("Suffix longer than string, sliceWithoutIndex", function () {
	// Suffix longer than string, slice without index check
	const string = '#lit#';
	const prefix = 'testingother'
	sliceWithoutIndex(string, prefix);
	});

	suite.on("cycle", function (evt) {
	console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
	console.log(new Array(30).join("-"));

	var results = evt.currentTarget.sort(function (a, b) {
	return b.hz - a.hz;
	});

	results.forEach(function (item) {
	console.log((idx + 1) + ". " + item);
	});
	});

	console.log("String startsWith another string #jsbench #jsperf");
	console.log(new Array(30).join("-"));
	suite.run();
	});