Alternative For Loops

We commonly use for loops to start at a numerical point and end at a numerical point, but they're not that rigid. In the below example we start with A, and on each loop we're adding B. Pretty cool if you ask me.

This

for (var start ="A"; start.length < 5; start = start + "B") {
    console.log(start)
}

Outputs

> A  
> AB  
> ABB  
> ABBB