I need to know, can't I develop Android application with only Java, without using C++. If we are going to start a carrer as Android developer, do I need to learn both C++ and Java. When develop industry application is Java enough?
Yes, you can develop Android apps with only Java, Java is enough. You're going to have to learn one thing at a time anyway... so you might as well learn Java first. If you find yourself thinking to yourself, "I'm going to need direct access to the underlying hardware and create my own 3D gaming engine... because this high level code isn't cutting it," then you can start learning C++.