Run results for: javascript loops over string

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser: Chrome 124

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 6 months ago

Test name	Executions per second
for-in	118605.7 Ops/sec
for-of	1531239.4 Ops/sec
for	6949163.0 Ops/sec
optimized-for	6917485.0 Ops/sec

Tests:

for-in
const items = 'abcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyz' let index = 0; for (let i in items) { index++; }
for-of
const items = 'abcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyz' let index = 0; for (let i of items) { index++; }
for
const items = 'abcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyz' let index = 0; for(let i = 0; i < items.length; ++i) { index++; }
optimized-for
const items = 'abcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyzabcdefghijklmopqrstuvwxyz' let index = 0; for(let i = items.length; i > 0; --i) { index++; }

Run results for: javascript loops over string

for-in

for-of

for

optimized-for