generate array contains 1 to 1e7

benchmark.js

console.time("Array.push");
const array = [];
for (var i = 0; i < 1e7; i++) array[i] = i;
console.timeEnd("Array.push");

console.time("new Array.push");
const array1 = new Array(1e7);
for (var i = 0; i < 1e7; i++) array1[i] = i;
console.timeEnd("new Array.push");

console.time("new Array.push rev");
const array2 = new Array(1e7);
for (var i = 1e7-1; i>=0; i--) array2[i] = i;
console.timeEnd("new Array.push rev");

console.time("Array.map");
const array3 = [ ...Array(1e7).keys() ].map((_, i) => i);
console.timeEnd("Array.map");

console.time("Array.from");
const array4 = Array.from({length:1e7},(_, i) => i);
console.timeEnd("Array.from");