Run results for: spread vs manual vs assign

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36

Browser: Chrome 140

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 11 months ago

literal

94K/s

spread

10K/s

assign

4K/s

View exact numbers

Test name	Executions per second
✓ literal	94,119 Ops/sec
spread	9,509 Ops/sec
assign	4,240 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

function mapObjectSpread(obj) {
    return {
        ...obj,
        id: obj.objId
    };
}

function mapObjectLiterally(obj) {
    return {
        objId: obj.objId,
        a: obj.a,
        b: obj.b,
        c: obj.c,
        id: obj.objId
    };
}

function mapObjectAssign(obj) {
    return Object.assign({}, obj, {
        id: obj.objId
    });
}

const objs = [];
for (let i = 0; i < 10000; i++) {
    objs.push({
        a: "a",
        b: "b",
        c: "c",
        objId: i
    });
}

Tests:

spread
objs.forEach(mapObjectSpread);
literal
objs.forEach(mapObjectLiterally);
assign
objs.forEach(mapObjectAssign);