Software Access Modifiers

Question 1

Access Modifiers

Answer 1

Access modifiers set the accessibility of classes, methods and other members. They determine whether other classes can use a particular field or invoke a particular method.

Question 2

Why use them?

Answer 2

The class interface clearly separates from the internal implementation - called encapsulation.

Security POV - stops class members from being changed in an uncontrolled way without proper validation

Programming POV - changes made to a public class variable could mean having to change the code everywhere

Question 3

Choosing Access Modifiers

Answer 3

Use the most restrictive access that makes sense for a particular class member.

Use private unless you have a good reason not to; avoid public except for constants which cannot be changed. Public fields restrict the code and limit flexibility.