I'm sorry, but I don't get this part: something.replace /^\/?/,'/' I'm a little sleepy, so maybe I'm missing something, but doesn't it replace a possible

I'm sorry, but I don't get this part: something.replace /^\/?/,'/' I'm a little sleepy, so maybe I'm missing something, but doesn't it replace a possible '/' at the beginning of some lines with '/'? Isn't that just a waste of CPU cycles? It effectively does nothing.