CS401

Java: Class Methods Part 2

Also see Part 1 about Methods

Have multiple methods of the same name but have different parameters either in number or type.

Example

This is the way in which methods that are inherited from a classes ancestors in the inheirantence chain are replaced or over-ridden by new methods.
Even if you have created a method that overrides a superclass's method, you can still call this superclasses method by using the following:
```
       super.method(); 
```

Exercise

optional method, a default exists that does nothing.
Special Kind of method called when creating an instance of a class that may perform any variety of operations including initializing variables, creating other objects, etc.
Always have the same name as the class.
Can have multiple constructors (overloaded) that take different inputs and can perform different operations.
Has NO return type.
If you write a class with a constructor with parameters and you intend to possibly use it as a Pareny class you need to make sure you also write a constructor with NO paramters. This is needed because: If the child class is defined with no constructors, it will automatically call super() which is the Parent's constructor with no arguments.
Inside of a constructor, if you need to call the parents constructor, you can do so by simply adding the following line inside of your constructor:
```
      super(arg1, ....); 
```

Exercise

Called just before the object is garbage-collected and its memory reclaimed. Must be defined as follows:
```
 protected void finalize() throws Throwable { ...}
```
NOTE: the throws Throwable refers to errors/exceptions that could occur....we will discuss this later when we talk about exceptions!!!
The default finalize() does nothing.
You can call a parent's finalize() using:
```
    super.finalize();
```
You can call finalize() yourself...it will not call the garbage collector.