Would I have much to gain if I learnt C++ or Java?I already know full-stack JS and c++ at an intermediate level. Plus some basic C.?

[Luis]

Hello, I would like to ask you a little question that has been in my head since just now, and I can not find an answer, would i have much to gain if i learnt c++ or java? i already know full-stack js and c++ at an intermediate level. plus some basic c. Please kindly inform me Help.