Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.97 Safari/537.36
Chrome 78
Windows
Desktop
5 years ago
Test name Executions per second
Using the spread operator 119728.6 Ops/sec
Using Array.prototype.concat 332437.1 Ops/sec
Script Preparation code:
x
 
var array1 = [];
var array2 = [];
for (let i = 0; i < 1000; i++) {
  array1[i] = Math.floor(Math.random() * 100);
  array2[i] = Math.floor(Math.random() * 100);
}
Tests:
  • Using the spread operator

     
    const array3 = [...array1, ...array2];
  • Using Array.prototype.concat

     
    const array3 = array1.concat(array2);