Java

In this article, we have presented several Interview Questions in Java (MCQ) covering all important topics in Java. These questions are frequently asked in Coding Interviews and you must attempt these questions.

Insanely growing demand for programmers comes with more and more competition in the field, and that ends up in "survival of the fittest". Even if you're a talented Java programmer already, there is always room for improvement.

TreeSet is created using the implementations of the SortedSet interface in Java and it uses Tree for storage.

StringBuilder is a standard library class in Java which can be used in handling string data and is alternative to String Buffer and String data type.

Scope of a variable in Java defines how a specific variable is accessible within the program or across classes. It is defined by the use of private, protected and public.

In this article, I have explained the String Pool in Java and how to implement it in Java programming. I have covered basic concepts of this topic. Also, I have explain the diagram.

Regex Expressions are a sequence of characters which describe a search pattern. It is generally used for 'find', 'find and replace' as well as 'input validation'. This article shall focus on how to write a Regex Expression in Java.

In this article, we have explored how to design the classical Snake Game using Object Oriented Programming (OOP) concepts and implement it using Java.

In Java, Strings are immutable which means that the existing String objects can't be changed i.e we can't modify the existing String objects or we can't change the internal state of the String objects.

Java has three sets of control statement that might be utilized to change the progression of execution of a program. The first set of statements is called selection statements followed by iteration statements and jump statements.

Command pattern is a behavioral-based design pattern that encapsulates a request/action in an object without knowing the internal operations. We have explored it in depth in Java.

Covariant return type in an Object oriented programming language means that the return type of any method can be replaced by a narrower type when it is overridden in the subclass or child class. We have explored it in Java in depth.

Java is an Object Oriented Programming language and supports the feature of inheritance. We cannot have Multiple Inheritance in Java directly due to Diamond Problem but it can be implemented using Interfaces.

In this article, we have explored how to make a Java code execute faster by handling Input and Output better. The ways we presented are Scanner class, BufferedReader class, User-defined FastReader Class and Reader Class.

The java.lang.String class provides a lot of methods to work on string. By the help of these methods, we can perform operations on string such as trimming, concatenating, converting, comparing, replacing strings etc. We have explored it in detail.

The 'this' keyword in Java is a reference ( which means it manages some relation ) to the current object where it is called. We have presented 6 usage of this keyword which includes referring to current class instance variable and much more.

In this article, we have explored Singleton design pattern in Java in depth and demonstrated several approaches each with its own advantages and shortcoming. We have explored related concepts like early and late initialization as well.

The three main elements of an exception handler in Java are: try, catch and finally block. We have explored these in depth with examples and questions related to handling exceptions in Java.

Super keyword, in Java, is used to call the Constructor of the Parent Class. It is required when we need to pass some arguments to Parent Class and complete object instantiation.

in this article, we have explored the basics of Abstract Window Toolkit (AWT) in Java which is used for creating Windows based Graphical User Interface. We demonstrated it by implementing a form UI using AWT in Java.

In this article, we have focused on 2D array in Java which is a variant of the usual 1D array by introducing a new dimension. We have demonstrated different operations with 2D arrays.

An Array List is a dynamic version of array and is supported in Java's collection library. In this article, we have focused on 2D array list in Java along with different methods applicable on it like indexOf.