Meanings
emphatic yes, used especially when someone asks the same question repeatedly
Und du bist dir auch wirklich sicher? – Ja doch! Ich sage dir doch, ich habe es mit eigenen Augen gesehen!So you’re really sure? – Yes! I’ve been telling you, I saw it with my own eyes!
expresses annoyance at a repeated question or a request, often translatable as come on
Und du hast ganz sicher die Schlüssel eingesteckt? – Ja doch, wie oft soll ich's denn noch sagen?And are you absolutely sure you’ve pocketed the keys? - Come on, how many more times do I have to say it?