Run results for: Spread Push VS Concat Reassign

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.122 Safari/537.36

Browser: Chrome 80

Operating system: Mac OS X 10.15.3

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Spread Push	3586215.2 Ops/sec
Concat Reassign	1724044.4 Ops/sec
Apply Push	3462351.0 Ops/sec

Script Preparation code:

var data = [
  1, 2, 3, 4,
  [1, 2, 3, 4],
  5, 6, 7, 8,
  [1, 2, 3, 4]
];

AخA
 
var data = [  1, 2, 3, 4,  [1, 2, 3, 4],  5, 6, 7, 8,  [1, 2, 3, 4]];

Tests:

Spread Push

(function fn(items){
  var result = [];
  items.forEach(item => {
    if(item.pop) {
      result.push(...fn(item));
    } else {
      result.push(item);
    }
  });
  return result;
})(data);

 
(function fn(items){  var result = [];  items.forEach(item => {    if(item.pop) {      result.push(...fn(item));    } else {      result.push(item);    }  });  return result;})(data);

Concat Reassign

(function fn(items){
  var result = [];
  items.forEach(item => {
    if(item.pop) {
      result = result.concat(fn(item));
    } else {
      result.push(item);
    }
  });
  return result;
})(data);

 
(function fn(items){  var result = [];  items.forEach(item => {    if(item.pop) {      result = result.concat(fn(item));    } else {      result.push(item);    }  });  return result;})(data);

Apply Push

(function fn(items){
  var result = [];
  items.forEach(item => {
    if(item.pop) {
      result.push.apply(result, fn(item));
    } else {
      result.push(item);
    }
  });
  return result;
})(data);

 
(function fn(items){  var result = [];  items.forEach(item => {    if(item.pop) {      result.push.apply(result, fn(item));    } else {      result.push(item);    }  });  return result;})(data);