Nowadays JavaScript has three different keywords to declare a variable — var, let and, const. Each has its own properties and particularities. Let’s start by making a simple comparison table of the ...

My understanding of Javascript scope is that every time $.getJSON succeeds, I should be allocating a new "slides" variable which contains the result of my JSON call. On Friday this is how it was ...

i.e. intuitively it looks like the variable will only be available within the block but it is accessible outside the block .. in javascript's case, because var doesn't make a block level declaration.