Hi everyone! I'm asking here because maybe you will know the answer of my question. I want to make mobile apps (mostly for Android), but I don't know how. Should I use Java or something else? Every answer will be appreciated :)
If you want to support multiple mobile platforms, you should check for multi platform development tools. There are quite a few but most are not free and the free ones are quite limited compared to the the options that the core SDKs of the vendors offer.
There are loads of alternatives to using the standard Android SDK.
Just play to your strengths. If you know Java then I would say go with the Android SDK(even though it may take time to learn if you haven't used it before). If you're more of a C# person and you've used XNA I would suggest MonoGame.... or you can use Unity.
If it were me I would go with MonoGame. Not only do I know C# MonoGame is free and allows you to port to many devices - not just the Android.
Java definitely, it is the language meant for it, and from what i've heard. It's simpler. However you can code in c++, I personally do not know Java but this topic has come up a lot all over. And majority of the people say Java because it's simpler and the intended language.
Can you tell me if I code on Java, can I write a simple program and run it on my android device immediately or I need to convert the code somehow?
What do you mean with "convert the code" ? Well... you will have to compile and build the application. Instead of compiling with the regular java compiler, just use the tools provided with the Android development kit.
These tools can be integrated with Java IDEs such as Eclipse or Intellij.
After the build you can either launch the application in an emulator or send it to your phone through the USB interface.