Run results for: Extract data from array - map() vs JSON.stringify() vs for loop

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.2.1

Device Platform: Mobile

Date tested: 2 years ago

Benchmark engine: Benchmark.js

map()

10.5M/s

ForLoop

2.3M/s

JSON.stringify()

1.2M/s

View exact numbers

Test name	Executions per second
✓ map()	10,479,632 Ops/sec
ForLoop	2,259,102 Ops/sec
JSON.stringify()	1,154,414 Ops/sec

Script Preparation code:

var data = [
    {name: "anonystick", sex:1, age: 42, phone: 03543214564},
    {name: "medium", sex:0, age: 45, phone: 0321452145},
    {name: "subrss", sex:1, age: 41, phone: 03789456785}
]

Tests:

map()
data.map(el => { return {name: el.name, sex: el.sex} })
JSON.stringify()
JSON.parse(JSON.stringify(data, ["name","sex"]))
ForLoop
var new_data = []; for (var i=0, new_data=[]; i<data.length; i++) { new_data.push({ name: data[i].name, sex: data[i].age }); }