Javascript Concatenate Array to String

Question

I am using D3.js and often find myself dynamically building transform attributes (or d attributes on path elements). Both of these of

Answer 1

When JavaScript coerces an array to a string, it actually call: .join(',') on the array. So you're actually going to be getting better performance with .join(',') manually as opposed to leaving it up to the interpreter to notice you're coercing the array. So: x + ',' + y is the fastest, [x, y].join(',') is the best practice(since it makes it easier to modify the behavior), and [x, y] is a tiny bit slower than manually calling .join and can be unreadable at times, but it's more convenient.