Run results for: Blaaaaaaaaaaaaaaargh

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Browser: Firefox 87

Operating system: Linux

Device Platform: Desktop

Date tested: 3 years ago

Script Preparation code:

data = [];
append = [];
for (let i = 0; i < 100; i += 1) {
    data.push(i.toString());
    append.push((1000 + 1).toString());
};

Tests:

Concat
for (let i = 0; i < 100; i += 1) { data.push("|"); data = data.concat(append); }
Spread
for (let i = 0; i < 100; i += 1) { data.push("|"); data.push(...append); }
loop
for (let i = 0; i < 100; i += 1) { data.push("|"); for (let j = 0; j < append.length; j += 1) { data.push(append[j]); }; }