-
}
}
public class test1 extends test
{
public void say()
{
super.hello();
hello();
}
public void main(String arg[])
{
test1 t = new test1();
t.say();
}
}
In the above code what will be difference of super.hello(); and hello();. What is use of super instead of calling directly method name.
">Public class test{ public void hello() { System.out.println("Helllo"); }}public class test1 extends test{ public void say(){ super.hello(); hello();}public void main(String arg[]){ test1 t = new test1(); t.say();}}In the above code what will be difference of super.hello(); and hello();. What is use of super instead of calling directly method name.
-
Which is the most convient way to create a thread and Why?1) Extends from thread or2) Implements from Runnable Interface.
nkkaushik
- Jan 5th, 2011
Impelementing the Runnable Interface gives a better way to create a Thread because by doing so, you can also extend any other class.
deepthis594
- Dec 27th, 2010
Implementing runnable is the most efficient way to create thread because classes should be extended only when they are being enhanced or modified in some way, while implementing runnable it is only required to override run method.
-
Why getInstance() method is used along with class declaration in Java?
komalnk
- Mar 1st, 2016
This is mainly used when there is need of creating an instance of the class.but, when the constructor of class is declared as private. (We cannot create object of object of such class, even inheritance is not possible). So, we use getInstance() method.
sunilbrahmajosyula
- Jan 5th, 2016
It mainly used in singleton class. In the singleton class we will be creating only one object. Where as this getInstance(); will make sure that there is only one copy of an Instance i.e.,copy of an object and returns the single object
-
-
-
Run Time Exceptions
What do exception mean in java ? what type of run time exceptions?
sanjusr25
- Jun 13th, 2009
Exception means an unwanted condition occur during the excecution of a program.Exception are of two type 1) Checked Exception2) Unchecked Exception Checked exception are those exception which can be...
ranaraj
- Dec 3rd, 2008
List of error exceptions are1).arithmetic Exception2).arrayindexoutofbounds?Exception3).arraystore?Exception4).filenotfoundException 5).ioException6).nullpointerException7).numberformatException8).outofmemoryException9).securityException10).stackoverflowException11).stringindexoutofboundsException
-
Nested and Inner Classes
What is the need of nested and inner classes in Java? Explain where they are useful?
Sarje
- Aug 20th, 2009
Using Inner classes you can write more efficient code and even reduce the typing work. Inner classes are frequently used in Event Handling. For example to MouseEvent event is handled in following exam...
msuresh70
- May 23rd, 2009
Nested class is static class wrapped inside the outer classInner class is non-static class wrapped inside the outer class which has access to the instance variables of outer class.
-
Which of the following options can be inserted at the commented line to compile the given code:
cpublic class Class1 {
Class1(String s){ }
Class1() { }
}
class Class2 extends Class1{
Class2(){ }
Class2(String s) {super(s);}
void m1() {
// insert code here
}
}
a) Class1 c1 = new Class1("HCL"){ }
b) Class1 c1 = new Class2(){ };
c) Class2 c3 = new Class1(String s){};
d) Class1 c1 = new Class1(100){ }; -
Print Only Numbers From Java Strings
I have a question in Java-string,
String s="adf5hgjyu1frdsff6vgyu7bnjh9asd3"; like
How to print only numbers in that stringVincent
- Jan 11th, 2018
Run someCode() method from main()
Code- span style="color: #0000ff;">"adf5hgjyu1frdsff6vgyu7bnjh9asd3""the number is "+n+" and it is ""Prime""Not Prime""Prime";
- }
rawatfeb
- Feb 23rd, 2016
private static void NumericsFromStringTest() { String alphaNumericString = "h8ll0"; char[] carray = alphaNumericString.toCharArray(); for (char c : carray) { if (Character.isDigit(c)...
-
Can a lock be acquired on a class
Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object..
derrick.paul
- Sep 12th, 2008
As your might already know, any synchronisation needs an object (monitor) to acquire lock one. See below for the three different types on how to synchronise code.public class A{ // A monitor obj...
-
What modifiers may be used with an inner class that is a member of an outer class
A (non-local) inner class may be declared as public, protected, private, static, final, orabstract.
priyam
- Oct 14th, 2022
It can have any access modifiers public ,private,protected,default like any ordinary top level class.
jigyasa_sienna
- Jun 7th, 2009
Public can be used as it is the only access modifier which can access?any class or methods from any class or package.
-
Is a class a subclass of itself
A class is a subclass of itself.
AGRAWALNIDHI
- May 2nd, 2009
No, a class can't be a subclass of itself. class A extends AThis is cyclic inheritance which is not possible.
-
-
-
What is the unit for 1000 in the below statement?ob.sleep(1000)
A) Int millisecondsB) Double millisecondsC) long millisecondsD) Float milliseconds
-
State true or false :- The word synchronized can be used with only a method.
A) FalseB) True
raghuprasad
- Aug 25th, 2008
False. The word synchronized can also be used to make a block of code synchronized.Eg: synchronized(object) { ............code........... }Raghu.
jagadeesh_32
- Aug 23rd, 2008
False, because synchronized keyword is used as block also.Ex:synchronized blocks can lock within code for just a few instructions and on any object whatsoever: synchronized (anyObject) { // .. object is handled atomically here }
-
Which of the following are true about the Error and Exception classes?
A) Both classes extend Throwable.B) The Error class is final and the Exception class is not.C) The Exception class is final and the Error is not.D) Both classes implement Throwable.
-
The term _____________ refers to a class's direct ancestor or to any of its ascendant classes.
Skill/Topic: InheritanceA) Sub ClassB) Super ClassC) Class hierarchy
-
Java I/O is based on the concept of _________
Skill/Topic: AWT & AppletsA) ClassesB) StreamsC) BuffersD) Threads
-
The concept of polymorphism is often expressed by the phrase
Skill/Topic: AWT & AppletsA) One interface, multiple methodsB) Multiple interface, one MethodC) Multiple interface, Multiple methodD) One interface, One method
Java Interview Questions
Ans