~96ms is this: A for loop creates a new lexical environment for variables, linked to the one outside it. One plausible explanation for that ~76ms vs. A test with Loop count: 3 gives me results like this (I wouldn't look at results for fewer than that many loops, there's delayed compilation and thread scheduling variability, etc.): For me on Chrome, they aren't that different (though they are clearly different and it's consistent). (And note that performance.now's return values will not be as fine-grained as they might be if snippets ran with Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp.)Ībout the unoptimized results: You've asked about A and B and why the unoptimized results are so different. To run another test, click Run code snippet again (to refresh so the environment is 'cold' again).Īgain, though, even that is a fairly naive way of benchmarking those loops. The test takes a while, please be patient. Strongly recommend not trusting results from fewer than 3 loops Const loopCount = loopCountInput.valueAsNumber Ĭonsole.log(`Running test with $ loop(s)`)

Javascript for loop