[danik.js]

Решил сравнить скорость )

(function() {


function test1() {

	for (var i=0; i<1000000; i++) {
		if (/2/.test(i)) {
			//console.log(i);
		}
	}
}

function test2() {

	function containsDigit(number, digit) {
		while (number > 0) {
			if (number % 10 == digit)
				return true;
			number = (number/10)|0;
		}
		return false;
	}

	for (var i=0; i<1000000; i++) {
		if (containsDigit(i, 2)) {
			//console.log(i);
		}
	}
}


var t1 = Date.now();
test1();
t1 = Date.now() - t1;

var t2 = Date.now();
test2();
t2 = Date.now() - t2;

alert("test1: " + t1 + ", test2: " + t2);

})();