Course Supervisor: Dr. Humera Tariq Hands on Lab Sessions: Ms. Sanya Yousuf

Size: px

Start display at page:

Download "Course Supervisor: Dr. Humera Tariq Hands on Lab Sessions: Ms. Sanya Yousuf"

Dorthy Rogers
5 years ago
Views:

1 Course Supervisor: Dr. Humera Tariq Hands on Lab Sessions: Ms. Sanya Yousuf

2 UML to represent and using single object Practice writing code for class Practice tostring( ) function Practice writing your own functions Practice Debugging Feature Practice building code logic Lab and Bonus Work

3 Task I: Write Code for RationalNumber.java so that given main( ) function executes successfully. Read instructions and slides for proper Lab completion

Study UML diagram for using Rational Numbers RationalNumberDemo + main (args : String[]) : void - Numerator: int - Denominator : int + RationalNumber( ) RationalNumber +

4 Study UML diagram for using Rational Numbers RationalNumberDemo + main (args : String[]) : void - Numerator: int - Denominator : int + RationalNumber( ) RationalNumber + RationalNumber(n:int,d:int) + RationalNumber(RationalNumber r) + add (q: RationalNumber) : void + add(int a):rationalnumber + tostring() : String Recall what are rational numbers

5 Open new Project and Recall Code Organization 1 Auto generated File created by Compiler and contains main ( ) function File RationalNumber.java is explicitly created by developer 2 We will test our object in main( ) after coding class RationalNumber.java

6 Write Code for RationalNumber.java. Open your Lectures and Recall we will write following functions. 1- Constructors Null Constructor Parameterized Constructor Copy Constructor 2- Setters and getter Functions void setnumerator(int n); void setdenominator(int d); void setrationalnumber(int n, int d); int getnumerator( ); int getdenominator( ); 3- Our desired functions - add two rational numbers - add a rational number with Integer - subtract two rational numbers - subtract an Integer from rational number 4- Methods to print/show our object - show( ) - tostring ( ) 3 Constructors,3 Setters 2 getters and 2 show methods

7 Kindly Put on your thinking cap and start coding in class RationalNumber.java

8 Recall the syntax of and purpose of show( ) and tostring( ). They present object Information to user. show( ) is user defined method tostring( ) is inherited method from built-in java class Object tostring( ) contains class attributes separated by + and

9 Put on your thinking cap again and start testing in class RationalNumberDemo.java Test/Run/call each function of RationalNumber.java inside main.java See Next Slide for Sample main( ) function and its execution

10 Modify class RationalNumber.java so that following main ( ) executes successfully. Please code line by line, resolve error then code further.

Denominator m = 3 4 + 5 4 m = 3 + 5 4 m = 8 4 Can your demonstrate what will happen in

11 Recall your can only code If you know its manual solution. Different Denominator m = x6 + (4x5) m = 4x6 m = m = Same Denominator m = m = m = 8 4 Can your demonstrate what will happen in Memory when add function call Occurs. If yes Draw it on your copy and show to teacher during Lab or in upcoming Theory Class.

12 Make Habit of overriding tostring() method in your class to print object using sout.

13 Task 2: Practice Debugging feature in every lab to resolve your errors on your own

14 Using Debug Feature: step into 1- Put mouse on gray area and click 2- Debug Project 3- step Into

15 Using Debug Feature: step over 4- step over 5- step over 6- step over 7- step over

16 Using Debug Feature: Reading Variables inside class add( ) function

17 Using Debug Feature: Reading Variables inside class main Memory Before step over 8- step over Memory after step over

18 Task I: Write Code for RationalNumber.java so that given main( ) function executes successfully. Read instructions and slides for proper Lab completion

19 Write function add (int a) in class RationalNumber.java and call it from main( ) function so that it execute successfully Is it function Overloading? (True/False) Explain why or why not? m = x1 + (2x24) m = 24x1 m = m = 86 24

21 Write function equalto (RationalNumber b) in class RationalNumber.java and call it from main( ) function as follows so that it execute successfully and gives accurate result.

22 Write function greaterthan (RationalNumber b) in class RationalNumber.java and call it from main( ) function as follows so that it execute successfully and gives accurate result.

23 1- What other important functions should be written in RationalNumber.java so that it becomes the best for users. Code any TWO such functions and discuss it in upcoming Theory Class. 2- Practice Coding class Point and class Line 3- write function fight( ) with proper paramters to class Wrestler of Lab 02. How you handle different moves like signature and finisher in your coding logic.

Inheritance and Polymorphism

Inheritance and Polymorphism Object Oriented Programming Designed and Presented by Dr. Ayman Elshenawy Elsefy Dept. of Systems & Computer Eng.. Al-Azhar University Website: eaymanelshenawy.wordpress.com Email : eaymanelshenawy@azhar.edu.eg