If German was seriously used in programming languages, I'd hope for some better and shorter terms. Some here might be intentionally too literal translations anyway. "Let" is from mathematics, it's called "Sei" in German. "Sei x = 5". "Anderenfalls" could be "sonst". "Zeichenkette" is just too long and would require some thinking or a historical accident to find a shorter term.

Ready surprisingly nice to me anyway.