What is the purpose of the Bundle class in Android?

Bundle is used for passing data between application components such as Activity, Fragment, or Service.

Main functions:

• Data storage: Can contain various primitive data types (int, boolean, String, etc.), arrays of primitives, as well as Parcelable or Serializable objects.
• Key-value pairs: Data is stored as key-value pairs, where the key is a string.
• State preservation: Used for saving and restoring the state of an Activity (for example, in onSaveInstanceState() and onRestoreInstanceState() methods).
• Fragment arguments: Used to pass arguments to a Fragment via the setArguments() method.
• Additional data in Intent: Allows passing additional data in an Intent using putExtra() and getExtras() methods.

Example of usage for passing data between Activities:

// Sending data from Activity A to Activity B
val intent = Intent(this, ActivityB::class.java)
val bundle = Bundle()
bundle.putString("username", "john.doe")
bundle.putInt("age", 30)
intent.putExtras(bundle)
startActivity(intent)

// Receiving data in Activity B
val extras = intent.extras
if (extras != null) {
    val username = extras.getString("username")
    val age = extras.getInt("age", -1) // Default value
}