What is the main purpose of using built-in functions and what are their advantages?

Built-in functions in Android (and in programming in general) are pre-implemented functions that can be used to perform common tasks. The main goal of their use is to increase development efficiency, reduce errors, and improve code readability.

Advantages:

• Time-saving: no need to write code from scratch.
• Optimization: functions are usually optimized and tested.
• Support and compatibility: built-in functions are supported by the platform and are updated.
• Readability: the code becomes clearer as functions have meaningful names.

For example, using the Toast.makeText() function to display a short message to the user instead of implementing pop-up notifications yourself.