[tinyhitman]

Could be to allow use of local variables that do not leak into the scope this code is executed in. That's what I use this pattern for.

[crdrost]

pro tip: no longer necessary

    { let count = 50; const interval = setInterval(() => { addSnakeNode(); if (--count <= 0) clearInterval(interval); }, 100) }

[londons_explore]

And polluting the global variable namespace hardly matters when using the console.