Array performance https://v8.dev/blog/elements-kinds#avoid-creating-holes
$ node -v
v14.14.0
$ node simple_loop.js
loop: 475.427ms
$ node null_check.js
loop: 474.855ms
$ node for_of.js
loop: 498.195ms
$ node for_each.js
loop: 474.051ms
$ node array_fill.js
array fill: 0.12ms
$ node array_fill_loop.js
array fill: 0.55ms
$ node array_fill_loop2.js
array fill: 0.36ms
$ node array_fill_map.js
array fill: 0.152ms
$ node max_check.js
999999
max: 12.62ms
$ node max_check2.js
999999
max: 12.719ms