"we cannot create an object of interface but we can create
a variable of it".diacuss the statement with the help of
an example.
Answers were Sorted based on User's Feedback
Answer / guest
1. Suppose interface interfaceDemo.java is as below
interface interfaceDemo {
public void methodA();
public void methodB();
}
2. Suppose class InterfaceDemoMain.java is as below
class InterfaceDemoMain implements interfaceDemo {
public void methodA() {
System.out.println("Inside methodA");
}
public void methodB() {
System.out.println("Inside methodB");
}
public void methodC() {
System.out.println("Inside methodC");
}
public static void main(String[] ar) {
InterfaceDemoMain idm = new InterfaceDemoMain();
interfaceDemo id;
id = idm;
id.methodA();
id.methodB();
id.methodC();// error
idm.methodC();
}
}
3. Here id.methodC(); will give error, only methods declared
inside interface are accessible to interface reference.
Is This Answer Correct ? | 13 Yes | 0 No |
yes we can create a variable in inerface
and i will be constant
mans to say that hey will be static and final
inerface Xyz
{
public static final i = 12;
public static final j = 20;
}
class Amit implements Xyz
{
psvm(String [] args)
{
Xyz k = new Amit();
System.out.println("value of var1 " + k.i);
Sysem.out.prinln("value ofd var 2 " + k.j);
}
}
Thanks ami singh
(amitsing2008@gmail.com)
Is This Answer Correct ? | 11 Yes | 0 No |
can we Connect Applet to Data Base ? with Discriptiom. and also What is Diff. from Applet & Servlet?
How to create an instance of a class if the class has private constructor?
what is meant by Byte code concept in Java?
What must a class do to implement an interface in java programming?
The following program reads data (details of students) from a file named students.txt and converts it into e-mail addresses. The results are written to a file named studentemail.txt. students.txt consists of a number of lines, each containing the data of a student in colon delimited format: Last Name:First Name:Student Number Each input record is converted to an e-mail address and written to studentemail.txt in the following format: the first character of the last name + the first character of the first name + the last four digits of the student number + “@myunisa.ac.za” import java.io.*; public class EmailConverter { public static void main(String[] args) throws IOException { BufferedReader input = new BufferedReader(new FileReader ("students.txt")); PrintWriter output = new PrintWriter(new FileWriter ("studentemail.txt")); String line = input.readLine(); while (line != null) { // Extract the information for each student String[] items = line.split(":"); // Generate the email address String email = "" + items[0].charAt(0) + items[1].charAt(0) + items[2].substring(4,8) + "@myunisa.ac.za"; email = email.toLowerCase(); // Output output.println(email); line = input.readLine(); } input.close(); output.close(); } } Rewrite the class so that it handles possible errors that may occur. In particular, it should do the following: • It should catch at least three appropriate exceptions that might occur, and display suitable messages. • At this stage, the program will not run correctly if there is an empty line in the input file. Change the program so that if an empty line is encountered, an exception is thrown and the empty line is ignored. This exception should be handled with the display of a suitable error message. • Before the e-mail address is added to the output file, check if the student number has 8 digits. If not, throw an InvalidFormatException (which the program should not handle itself)
What is module in project?
Why is the main method declared static?
tell me some common
where to use join method and explain with real time senario?and programatical explenation also..
What is method overriding in java ?
what are the jsp tags with example?
Define immutable object?