Run results for: Object rename: reduce vs fromEntries vs assign & delete

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36

Browser: Chrome 145

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 5 months ago

reduce

8.5M/s

fromEntries

4.4M/s

assign & delete

10K/s

View exact numbers

Script Preparation code:

obj = { "a": 1, "b": 'string', c: {hi:'ho'} };
prefix = "_";

Tests:

reduce
return Object.keys(obj).reduce(function (result, key) { result[prefix + key] = obj[key]; return result; }, {});
fromEntries
return Object.fromEntries( Object.entries(obj).map(([k, v]) => [`${prefix}${k}`, v]) )
assign & delete
for (const key in obj) { obj[prefix+key] = obj[key]; delete obj[key]; }