Run results for: javascript loops over string

Test name	Executions per second
✓ optimized-for	5,034,590 Ops/sec
for	5,033,229 Ops/sec
for-of	688,012 Ops/sec
for-in	21,573 Ops/sec

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++;
}