Why not a public variable, but get/set functions?

Question

Java

Why is it worth using get/set if the variable can be used in any way?

Answer 1

This is called a growth point, you leave the method so that you can then add something to it.
For example, updating some construction after assigning a number more than 10 to a variable, what will you do if the variable is public? Rewrite all the code where it was used?

Answer 2

Setters often do value checks and validations; in the case of getters, they can combine the values ​​of multiple fields. The logic changes in one place, not many.
Java libraries, such as serialization, and therefore frameworks based on them, use getters and setters

Answer 3

I highly recommend Joshua Bloch - Effective Java 2nd Edition, Item 14.

Answer 4

Not always worth it.