Question

Not really an immediate source code question per se….but Im looking into doing some casual Android Programming, nothing heavy.

But it seems to use alot of XML and Java……what I wonder though is why is it that android is written mostly in C and XML (along with C++ and Java) with it being closely related to the Linux OS……but why is the “main” language for programming in android Java?

Just out of curiosity of course.

Answer 1

The “main” language, as you called it, is Java. You can use C/C++ via the NDK, but you won’t need it unless you are doing some special stuff. If you wonder when you would need to use C/C++, take a look at the official documentation:

When to Develop in Native Code

The NDK will not benefit most applications. As a developer, you need to balance its benefits against its drawbacks; notably, using native code does not result in an automatic performance increase, but always increases application complexity. In general, you should only use native code if it is essential to your application, not just because you prefer to program in C/C++.

Typical good candidates for the NDK are self-contained, CPU-intensive operations that don’t allocate much memory, such as signal processing, physics simulation, and so on. Simply re-coding a method to run in C usually does not result in a large performance increase. When examining whether or not you should develop in native code, think about your requirements and see if the Android framework APIs provide the functionality that you need. The NDK can, however, can be an effective way to reuse a large corpus of existing C/C++ code.

The Android framework provides two ways to use native code:

• Write your application using the Android framework and use JNI to access the APIs provided by the Android NDK. This technique allows you to take advantage of the convenience of the Android framework, but still allows you to write native code when necessary. You can install applications that use native code through the JNI on devices that run Android 1.5 or later.

• Write a native activity, which allows you to implement the lifecycle callbacks in native code. The Android SDK provides the NativeActivity class, which is a convenience class that notifies your native code of any activity lifecycle callbacks (onCreate(), onPause(), onResume(), etc). You can implement the callbacks in your native code to handle these events when they occur. Applications that use native activities must be run on Android 2.3 (API Level 9) or

You cannot access features such as Services and Content Providers natively, so if you want to use them or any other framework API, you can still write JNI code to do so.