DAY 23 5.2 OVERLOADING

Overloading: allows for making several methods with

the same name (method heading) which diff er from

each other in the type of the input and the output of

the function.

It is simply defined as the ability of one function to

perform diff erent tasks.

OVERLOADING IN CODING (RHYMES)

For example, doTask() and doTask(int income) are overloaded

methods. To call the latter, an integer must be passed as a

parameter, whereas the former does not require a parameter,

and is called with an empty parameter fi eld. A common error

would be to assign a default value to the integer in the

second method, which would result in an ambiguous call

error, as the compiler wouldn't know which of the two

methods to use.

OVERLOADING IN CODING (RHYMES)

Example 2: consider the following two methods,

public void print(String word)

and

public void print(String sentence)

Example 2: consider the following two methods,

public void print(String word)

and

public void print(String sentence)

^ These are overloaded methods as compiler doesn’t know which method to call. Outcome: nothing will be printed!

// volume of a cube

int volume(int s) { return(s*s*s); }

// volume of a cylinder double volume(double r,int h) { return(3.14*r*r*h); }

EXAMPLE 3

Excessive overloading may be diffi cult for developers

to understand which overloaded method is being

called simply by reading the code.

OVERLOADING MAKES IT DIFFICULT TO READ CODE

public class AddAmount{ public int mathItems(int a, int b) { return a + b; }

public int mathItems(int c, int d){ return c+c+d+d;}

EXAMPLE 4 – COMPILER CONFUSION

ANY QUESTIONS?

WORK ON ASSIGNMENT #2