snippet.js

const array1 = [];

// adding 100k elements to array1
for (let i = 0; i < 500000; i++) {
  array1.push(i);
}

// creating a copy of the array1 variable
const array2 = [];
// adding one element at a time
array1.forEach((e) => {
  array2.push(e);
});

console.log(array2.length); // 500000