Run results for: loop length recalculation - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36 Edge/15.15063

Browser: Chrome 52

Operating system: Windows

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
normal loop	3.9 Ops/sec
loop without length	4.9 Ops/sec
reverse loop	4.9 Ops/sec
weird trick	4.4 Ops/sec

Website performance monitoring

Script Preparation code:

  var arr=new Array(1000000).fill(0)

Tests:

normal loop
for (var i=0;i<arr.length;i++){val=arr[i]}
loop without length
var l=arr.length; for (var i=0;i<l;i++){val=arr[i]}
reverse loop
for (var i=arr.length;i>0;i--){val=arr[i]}
weird trick
for (var i=arr.length;i>0;i--){val=arr[i]|0}