Where in the code should variable definitions be placed directly at runtime?

Runtime variable definitions are usually placed in parts of the code where they are directly needed and where their values can change dynamically.

In Android, this is often:

• Inside methods, for example, in onCreate(), onClick(), and other event handlers.
• In code blocks where logic depends on the application state or user input.

This approach helps limit the scope of the variable and improves code readability.

Example:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val userName = intent.getStringExtra("USER_NAME") // defining a variable at runtime
    // use userName further
}