Run results for: Caching length property (internal and external) vs getting it each time in the loop, v2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36

Browser: Chrome 101

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Cache length (external)	721.4 Ops/sec
No cache	340.5 Ops/sec
Cache length (internal)	651.4 Ops/sec
Reverse loop, internal cache (var)	683.0 Ops/sec
Reverse loop, internal cache (let)	691.5 Ops/sec

Script Preparation code:

var arr = [];
var count = 10000;
for(var i = 0; i<count; i++)
{
  arr.push(i);
}

Tests:

Cache length (external)
var arrLen = arr.length; var sum = 0; for (var i = 0; i < arrLen; i++){ sum = arr[i]; }
No cache
var sum = 0; for (var i = 0; i < arr.length; i++){ sum = arr[i]; }
Cache length (internal)
var sum = 0; for (var i = 0, arrLen = arr.length; i < arrLen; i++){ sum = arr[i]; }
Reverse loop, internal cache (var)
var sum = 0; for (var i = arr.length; i--; ){ sum = arr[i]; }
Reverse loop, internal cache (let)
let sum = 0; for( let i = arr.length; i--; ){ sum = arr[i]; }