Run results for: Array loop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36

Browser: Chrome 57

Operating system: Windows

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Standard For loop i++	4.1 Ops/sec
Standard For loop i--	6.1 Ops/sec
While, i--	2.3 Ops/sec
While, with 8 iterations, with function call	21.9 Ops/sec
While, with 8 iterations, without function call	28.5 Ops/sec
While, with 50 iterations, with function call	143.8 Ops/sec

Script Preparation code:

var loopItems = [];
var i = 0;

for (i = 0; i < 1000000; i++) {
	loopItems.push(Math.random());
}

var process = function (i) {
	i++;
}

Tests:

Standard For loop i++
i = loopItems.length; for (var j = 0; j < i; j++) { process(loopItems[j]); }
Standard For loop i--
i = loopItems.length; for (var j = i; j > 0; j--) { process(loopItems[j]); }
While, i--
i = loopItems.length; while (i) { process(loopItems[i--]); }
While, with 8 iterations, with function call
i = Math.floor(loopItems.length / 8); while (i) { process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); }
While, with 8 iterations, without function call
i = Math.floor(loopItems.length / 8); while (i) { loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; loopItems[i--]++; }
While, with 50 iterations, with function call
i = Math.floor(loopItems.length / 50); while (i) { process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); process(loopItems[i--]); }

Run results for: Array loop

Standard For loop i++

Standard For loop i--

While, i--

While, with 8 iterations, with function call

While, with 8 iterations, without function call

While, with 50 iterations, with function call