Run results for: Flatten Array of Arrays

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
concat apply	748861.1 Ops/sec
ES6 spread	762296.8 Ops/sec

Script Preparation code:

var arr = (new Array(50)).map(() =>{
  let len = Math.floor(Math.random() * 1000) + 1;
  return (new Array(len)).map((v,i) => {return i});
});

AخA
 
var arr = (new Array(50)).map(() =>{  let len = Math.floor(Math.random() * 1000) + 1;  return (new Array(len)).map((v,i) => {return i});});

Tests: