This unit is about objects

By the end of this unit you should know

• what static means
• ★ static vs instance vs local variables
• static vs instance methods
• the difference between public, default and private access
• getters and setters
• how to create a constructor
• why one would make a constructor private
• how one constructor can call another Not on this test
• how and why to write a .toString() method
• how to make a constant in Java
• how to make subclasses (more needed here about inheritance and polymorphism)
• how to check if two objects are equal (write a equals() method) Not on this test
• how to use @Override (and how to override methods)
• overriding variables (don't do it) and methods
• super, this, final
• hiding vs overriding and also this page: http://javainsimpleway.com/variable-hiding-in-java/ Not on this test
• overriding vs overloading Not on this test
• inner classes
• anonymous inner classes Not on this test
• ★ null pointer errors

You might want to look over the modifiers page as well.