Run results for: flatten reduce vs for .. of vs reduce TCO v2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser: Chrome 121

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

for of

7K/s

reduce TOC

7K/s

reduce

5K/s

View exact numbers

Test name	Executions per second
✓ for of	6,907 Ops/sec
reduce TOC	6,893 Ops/sec
reduce	5,450 Ops/sec

Script Preparation code:

const get = (depth = 0) => {
    const arr = [];
    if (depth > 100) { // Stop recursion beyond depth 2
        return arr; // Return an empty array to avoid undefined entries
    }
    for (let i = 0; i < 10; i++) { // Reduced loop count for demonstration
        if (Math.random() > 0.2) {
            // Recursively call get(), but wrap the result in an array to ensure arrays are nested within
            arr.push([get(depth + 1)]);
        } else {
            // Create a sub-array of numbers
            const numberArray = [];
            for (let j = 0; j < 100; j++) {
                numberArray.push(Math.floor(Math.random() * 100));
            }
            // Decide randomly to push the whole array or individual numbers
            if (Math.random() > 0.5) {
                arr.push(numberArray); // Push the array as a single element
            } else {
                arr.push(...numberArray); // Spread the array into individual elements
            }
        }
    }
    return arr;
};

var array = get(99)

Tests:

reduce
const flatten = (arr) => arr.reduce((acc, x) => { Array.isArray(x) ? flatten(x).forEach(y => acc.push(y)) : acc.push(x) return acc; }, []) const x = flatten(array);
for of
const flat = (argarr) => { let arr = [] for (const item of argarr) { if (Array.isArray(item)) arr = arr.concat(flat(item)) else arr.push(item) } return arr } const x = flat(array);
reduce TOC
const flatten = (arr, acc = []) => { arr.forEach(x => { if (Array.isArray(x)) { flatten(x, acc); } else { acc.push(x); } }); return acc; }; const x = flatten(array);