"types & grammar": cover what `Array(3)` is actually doing

[getify]

"types & grammar": cover what `Array(3)` is actually doing

[JakeChampion]

I decided to see what happens if you copy the array into itself. This was the result:

var a = Array(3);
console.log(a); // [undefined × 3]
a[1] = a; // [undefined × 1, Array[3], undefined × 1]
a[1][1] // [undefined × 1, Array[3], undefined × 1]
a[1][1][1] // [undefined × 1, Array[3], undefined × 1]
a[1][1][1][1][1][1][1][1][1][1][1] // [undefined × 1, Array[3], undefined × 1]

This seems to create an infinite series of nested arrays, I have no idea why though. Any ideas?

I used the Chrome DevTools to test this out.

[cirocosta]

@JakeChampion, This is Circular Reference. In NodeJS it simplifies to [Circular]. So, doing that with node you'll get:

a[1] = a;    // [ , [Circular]  ,]