Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
Java Articles
Page 445 of 450
What is a method in Java that ends in a semicolon and has no method body?
An abstract method is the one which has no definition and declared abstract. In short, an abstract method contains only method signature without body. To use this method, you need to inherit this method by extending the class and provide the method definition. Example public abstract class Employee{ private String name; private String address; private int number; public abstract double computePay(); }
Read MoreWhat is Callable interface in Java?
The Callable interface is found in the package java.util.concurrent. The Callable object can return the computed result done by a thread in contrast to a runnable interface which can only run the thread. The Callable object returns a Future object which provides methods to monitor the progress of a task being executed by a thread. The future object can be used to check the status of a Callable and then retrieve the result from the Callable once the thread is done. It also provides timeout functionality.
Read MoreWhat is the difference between Component class and Container class in Java?
The class Component is the abstract base class for the non-menu user-interface controls of AWT. A component represents an object with graphical representation. The class Container is the superclass for the containers of AWT. The container object can contain other AWT components.
Read MoreCan you use both this() and super() in a constructor in Java?
No, you cannot have both this() and super() in a single constructor.
Read More
Why can’t we override static methods in Java?
Overloading is the mechanism of binding the method call with the method body dynamically based on the parameters passed to the method call.Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.
Read MoreWhat are tokens in Java?
Java tokens are smallest elements of a program which are identified by the compiler. Tokens in java include identifiers, keywords, literals, operators and, separators.
Read MoreCan a Java array be declared as a static field, local variable or a method parameter?
We can declare an array as a local variable or method parameter but, an array cannot be static. Example public class Test{ public void sample(){ static int[] myArray = {20, 30}; System.out.println(); } public static void main(String args[]){ Test t = new Test(); t.sample(); } } Error C:\Sample>javac Test.java Test.java:3: error: illegal start of expression static int[] myArray = {20, 30}; ^ 1 error
Read MoreCan access modifiers be used for local variables in Java?
Yes, a local variable can be public, private, protected or default.
Read MoreWhat is the difference between a String object and a String literal in Java?
When the String literal used to create String, JVM initially checks weather String with the same value in the String constant pool, if available it creates another reference to it else it creates a new object and stores it in the String constant pool.In case of an object, each time you instantiate the class a new object is created given value irrespective of the contents of the String constant pool.
Read More