[robcee]

I was aware it's pretty modern but honestly didn't think about it much. We use it heavily in Firefox Devtools code and I much prefer its non-hoisting properties over var.

[iMark]

Out of curiosity, what do you mean by non-hoisting properties? According to the MDN docs let variables are hoisted, at least to the enclosing block.

[robcee]

I usually think of "hoisting" as promoting a var outside of its containing scope to within the next block.

e.g.,

function() { var a = 2; // b is visible here if (a == 2) { var b = 3; } }

[iMark]

Hoisting still occurs within a scope such that, for example, a function defined at the end of a block can be called at the top.

[robcee]

right. The point I was trying to illustrate was that the inner variable declared with a "var" keyword was visible outside its containing block. If I'd used "let" there, it would not be.