CSE Lecture 14/Jan/2008

Method Overloading

You are allowed to have more than one method with the same name. as long as the methods with the same name take different numbers and/or types of parameters.

All methods with the same function may have the same name. This reduces confusion.

e.g. a method that squares a number, without overloading:

public static int SquareInt(int x)
{ return x * x;}
public static double SquareDouble(double x)
{return x * x;}

With overloading:

public static int square(int x)
{return x * x;}
public static double square(double x)
{return x * x;}

For Java to use one method over another is called "overriding."

Overloaded methods provide for default parameters, and should call each other.

Interfaces as Parameters

Interface: a specification for a class containing method declarations.

A class that is declared to implement the interface must implement those methods exactly as specified.

e.g. Comparable

int compareTo(Object o)

Object a implements Comparable, as well as object b.

int x = a.compareTo(b);

If a > b, x > 0
If a < b, x < 0
If x == b, x == 0

Method "printCompare" takes two arguments and prints to the screen whether one argument is greater than the other. This is typically an easier method to implement.