Steps to follow:
1. Modify Main.java as shown below in Code-11.2.a under personpackage directory. (You are welcome to do this work using either command line tools or NetBeans. The instruction for using NetBeans is given below.) The code fragment that needs to be added is highlighted in bold and blue-colored font.
* cd \myjavaprograms
* jedit personpackage\Main.java
package personpackage;
public class Main {
public static void main(String [] args ){
Student student1 =new Student();
// Calling methods defined in Person class, which is a parent class of Student class
student1.setName("Sang");
System.out.println("Calling getName() method: name is " + student1.getName());
}
}
Code-11.2.a: Modified Main.java
2. Compile and run the code using a directory structure.
* cd \myjavaprograms
* javac personpackage\*.java
* java -classpath . personpackage.Main
3. Verify the result is as following
* C:\myjavaprograms>java -classpath . personpackage.Main
Inside Person:Constructor
Inside Student:Constructor
Person: getName()
Calling getName() method: name is Sang
5. Modify the Student.java as shown below in Code-11.2.b. The Student class is overriding the getName() method of its parent class, Person class. The code fragment that needs to be added is highlighted in bold and blue-colored font.
* cd \myjavaprograms
* jedit personpackage\Student.java
package personpackage;
public class Student extends Person {
private String hobby;
public Student(){
System.out.println("Inside Student:Constructor");
}
public String getHobby(){
return hobby;
}
public void setHobby(String s){
hobby = s;
}
// Override getName() method of the parent class
public String getName(){
System.out.println("Student: getName()");
return "Passionate" + super.getName();
}
}
Code-11.2.b: Modified Student.java
6. Compile and run the code using a directory structure.
* cd \myjavaprograms
* javac personpackage\*.java
* java -classpath . personpackage.Main
7. Verify the result is as following
* C:\myjavaprograms>java -classpath . personpackage.Main
Inside Person:Constructor
Inside Student:Constructor
Student: getName()
Person: getName()
Calling getName() method: name is PassionateSang
Steps to follow if you are using NetBeans
1. Modify the Main.java as shown in Code-11.2.a.
2. Right click personpackage package node (not PersonPackage project node) and select Compile Package (F9)
3. Right click Main select Run File
4. Modify the Student.java as shown in Code-11.2.b.
5. Right click personpackage pacakge node (not PersonPackage project node) and select Compile Package (F9)
6. Right click Main select Run File
Homework:
1. In your TuftsStudent class, override getHobby() and setHobby() methods of the Student class as following
* public String getHobby(){
System.out.println("Inside TuftsStudent:getHobby() method");
return "My hobby is " + super.getHobby();
}
public void setHobby(String s){
System.out.println("Inside TuftsStudent:setHobby() method");
super.setHobby(s);
}
2. Change Main.java to invoke setHobby() and getHobby() methods of the newly created TuftsStudent object instances as followoing.
* // set hobbies of student2 and student3
student2.setHobby("swimming");
student3.setHobby("dancing");
// get hobbies of student2 and student3
String hobby2 = student2.getHobby();
System.out.println("Hobby of student2 " + hobby2);
String hobby3 = student3.getHobby();
System.out.println("Hobby of student3 " + hobby3);
3. Compile and run the code. You should see the following result.
* Inside Person:Constructor
Inside Student:Constructor
Inside Person:Constructor
Inside Student:Constructor
Inside TuftsStudent:Constructor
Inside Person:Constructor
Inside Student:Constructor
Inside TuftsStudent:Constructor
Inside TuftsStudent:setHobby() method
Inside TuftsStudent:setHobby() method
Inside TuftsStudent:getHobby() method
Hobby of student2 My hobby is swimming
Inside TuftsStudent:getHobby() method
Hobby of student3 My hobby is dancing
Popular Posts
-
Arguments passed by value and by reference. Until now, in all the functions we have seen, the arguments passed to the functions have been pa...
-
SQL Server Express is a free, easy to use, redistributable version of SQL Server 2005 designed for building simple data-driven applications....
-
Declaration of variables In order to use a variable in C++, we must first declare it specifying which data type we want it to be. The syntax...
-
Syntax of JSP Scriptles are: <% //java codes %> JSP Scriptlets begins with <% and ends %> .We can embed any a...
-
The SQL ORDER BY clause comes in handy when you want to sort your SQL result sets by some column(s). For example if you want to select all t...
-
STRINGS: The way a group of integers can be stored in an integer array, similarly a group of characters can be stored in a character array. ...
-
Java Server Pages JavaServer Pages (JSP) technology is the Java platform technology for delivering dynamic content to web clients in a por...
-
DIFFERENCE BETWEEN STRUCT AND UNION: In structures,each member has its own storage location,whereas all memebers of a union use the same loc...
-
SQL is short for Structured Query Language and is a widely used database language, providing means of data manipulation (store, retrieve, up...
-
Inheritance A key feature of OOP is reusability. It's always time saving and useful if we can reuse something that already exists rather...
No comments:
Post a Comment