Run results for: literal, literal spread, vs reuse

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser: Chrome 126

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Script Preparation code:

arr = [];
for (let i = 0; i < 10000; i++) {
arr.push({
  a: Math.random(),
  b: Math.random(),
  c: Math.random()
})
}
total = 0;

Tests:

literal spread
const k = Math.random(); total += arr.map((obj) => { return { ...obj, d: obj.a + obj.b + k, }; }).reduce((total, obj) => { return total + obj.d / obj.c; }, 0);
reuse
const k = Math.random(); const r = { a: 0, b: 0, c: 0, d: 0, }; total += arr.map((obj) => { r.a = obj.a; r.b = obj.b; r.c = obj.c; r.d = obj.a + obj.b + k; return r; }).reduce((total, obj) => { return total + obj.d / obj.c; }, 0);
literal
const k = Math.random(); total += arr.map((obj) => { return { a: obj.a, b: obj.b, c: obj.c, d: obj.a + obj.b + k, }; }).reduce((total, obj) => { return total + obj.d / obj.c; }, 0);