Java Tutorial

Java Tutorial Java Features C++ vs Java Java History Java Hello World Java Development Kit Java Runtime Environment Java Virtual Machine Difference between JDK, JRE, and JVM Memory Areas in Java Java Operators Java Keywords Primitive Data Types Variables

Java Loops

Java Do While Loop Java While Loop Java For Loop Java Enhanced For Loop

Java Programs

Java Basic Programs Factorial Program in Java Fibonacci Series Program in Java Prime Number Program in Java Palindrome Number Program in Java Armstrong Number Program in Java Anagram Program in Java Pattern Programs in Java Calculator Program in Java Leap Year Program in Java Addition Program in Java Number Pattern Programs in Java Star Pattern Programs in Java Package Program in Java Pyramid Program in Java Sorting Program in Java String Palindrome Program in Java Even Odd Program in Java For Loop Program in Java If Else Program in Java Switch Case Program in Java GCD Program in Java LCM Program in Java Hello Program in Java Matrix Program in Java Menu Driven Program in Java Series Program in Java Client Server Program in Java Swapping Program in Java Pig Latin Program in Java Tower of Hanoi Program in Java Recursion Program in Java Matrix Multiplication Program in Java Perfect Number Program in Java Classes and Objects in Java Example Programs String Programs in Java Array Programs in Java Constructor Program in Java Inheritance Program in Java Abstract class Program in Java Interface Program in Java Encapsulation Program in Java Polymorphism Program in Java Exception Handling Program in Java Multithreading Program in Java Thread Program in Java Collection Programs in Java ArrayList Program in Java Stack Program in Java Applet Program in Java Swing Program in Java JDBC Program in Java How to run Java program in command prompt How to run Java program in Eclipse

Java Sorting

Sorting Algorithms in Java Merge Sort in Java Quick Sort in Java Bubble Sort in Java Insertion Sort in Java Selection Sort in Java Heap Sort in Java Radix Sort in Java Topological Sort in Java Bucket Sort in Java Counting Sort in Java

Java OOPs Concepts

OOPs - Object Oriented Programming Objects and Classes in Java Java Naming Conventions Constructors in Java Java this keyword Java static keyword Inheritance in Java Aggregation in Java Java super keyword Constructor Chaining and Constructor Overloading Java Polymorphism Static and Dynamic Binding in Java Java Abstraction Abstract class in Java Interface in Java Difference between Abstract class and Interface Java final keyword Packages in Java Access Modifiers in Java Java Wrapper classes Java Numbers Java Characters Java Integer Java Boolean Java Arrays Java Command Line Arguments Java strictfp Keyword Java Math

Java Strings

Java Strings Java String Methods StringBuilder in Java StringBuffer in Java Java Regular Expressions StringBuffer vs StringBuilder String vs StringBuffer String vs StringBuilder String Manipulation in Java Java String Concatenation How to Reverse a String in Java String Array in Java How to Compare Two Strings in Java How to Concatenate Two Strings in Java Why String in Immutable in Java java.lang.NumberFormatException for Input String String Pool in Java Java Generate Random String How to take String Input in Java Java String Interview Questions

Java Exceptions

Exception Handling in Java Java try catch Java throw Java throws Difference between throw and throws Java finally Java Custom Exception Java Exception Propagation

Garbage Collection

Automatic Resource Management in Java Java Garbage Collection Java finalize() Java gc() Difference between final, finally and finalize


Multithreading in Java Process and Thread in Java Basic Terms in Multithreading Java Thread creation Thread Scheduler in Java Java Thread class DeadLock in Java

Java IO

Java IO Java Read File Java BufferedWriter Java InputStreamReader Java File Java Read File Line By Line Java FileOutputStream Jar File in Java


Java Serialization Java transient


Java Network Programming Java Socket Programming Java URL Java URLConnection HttpURLConnection in Java Java InetAddress Java DatagramSocket and Java DatagramPacket


Java AWT


Swing in Java

Java Collections

Collections in Java Java List Interface ArrayList in Java LinkedList in Java Vector in Java Stack in Java ArrayList vs LinkedList in Java ArrayList vs Vector in Java Java Set Interface HashSet in Java LinkedHashSet in Java TreeSet in Java Java Queue Interface PriorityQueue in Java ArrayDeque in Java Java Map Interface HashMap in Java LinkedHashMap in Java TreeMap in Java Dictionary in Java Hashtable in Java Properties in Java Collections class in Java Java Comparable Java Comparator Comparable vs Comparator in Java

Java Generics

Generics in Java

Java Annotations

Annotations in Java


Java JDBC Tutorial

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Static vs Non-static in Java C vs Java int vs Integer in Java Stack vs Heap in Java Java Array vs ArrayList

How to

How to run Java program How to set path in Java How to check the Java version in cmd How to install Java in Windows 10 How to run Java program in cmd How to call a method in Java How to sort an array in Java How to iterate HashMap in Java How to write Java program How to create an array in Java How to create a package in Java How to generate random numbers in Java How to input String in Java How to create thread in Java How to find length of String in Java How to sort a string in Java How to use scanner in Java How to achieve multiple inheritance in Java How to run Java program in Eclipse How to call a function in Java How to create array of objects in Java How to create custom exception in Java How to achieve abstraction in Java How to call static method in Java

Java 8 Features

Java 8 Features Lambda Expressions in Java Functional Interface in Java Streams in Java Java Base64 Encoding and Decoding Parallel Arrays Sort in Java

Java 9 Features

Java 9 Tutorial Java 9 Try With Resources Java 9 Interface Private Method

Java Servlet Tutorial

Java Servlets Tutorial

Java JSP Tutorial

Java JSP Tutorial

Hibernate Tutorial

Hibernate Tutorial

Spring Tutorial

Spring Tutorial

Spring MVC Tutorial

Spring MVC Tutorial

Jenkins Tutorial

Jenkins Tutorial

Java Math Methods

Math.abs() Math.acos() Math.addExact() Math.asin() Math.atan () Math.atan2() Math.cbrt() Math.ceil() Math.copysign() Math.cos() Math.cosh() Math.decrementExact() Math.exp() Math.expm1() Math.floor() Math.floorDiv() Math.floorMod() Math.getExponent() Math.hypot() Math.IEEEremainder() Math.incrementExact() Math.log() Math.log10() Math.log1p() Math.max() Math.min() Math.multiplyExact() Math.multiplyFull() Math.negateExact() Math.nextAfter() Math.nextDown() Math.nextUp() Math.pow() Math.random() Math.rint() Math.round() Math.scalb() Math.signum() Math.sin() Math.sinh() Math.sqrt() Math.subtractExact() Math.tan() Math.tanh() Math.toDegrees() Math.toIntExact() Math.toRadians() Math.ulp()

Java String Methods

toCharArray() copyValueOf() endsWith() equals() equalsIgnoreCase() format() getBytes() getChars() hashCode() indexOf() intern() isEmpty() join() lastIndexOf() length() replace() replaceAll() replaceFirst() split() startsWith() subSequence() substring() toLowerCase() toUpperCase() trim() valueOf()

Java Conversion

Java Convert String to int Java Convert int to String Java Convert String to long Java Convert long to String Java Convert String to float Java Convert float to String Java Convert String to double Java Convert double to String Java Convert String to Date Java Convert Date to String Java Convert String to Object Java Convert Object to String Java Convert String to char Java Convert char to String Java Convert int to long Java Convert long to int


Functional Interfaces in Java Singleton class in Java Awesome explanation of Strings in Java Object class in Java Static class in Java All the important string methods in Java String Handling Method in Java What are Array strings in Java Advantages and Disadvantages of Strings in Java Big Decimal class in Java Class definition in Java Char and String differences in Java Difference between String, StringBuffer and StringBuilder in java Replace character in string Java String Coding Interview Questions in Java What is String in Java? String isnullorempty in Java String Matches in Java Trim Method in String Java Bean class in Java Libraries in Java Arithmetic Operations on String in Java

Class definition in Java

The class definition in Java

Java is an object-oriented programming language. We essentially know that programming languages based on object-oriented paradigms have classes and objects in their concepts as main, which is quite significant.

They are different kinds of classes available in Java in a subtle way. Classes particularly are defined as a code that defines the implementation of the algorithm and logic used by the programmer to achieve a desired result or output in a very big way.

As Java is an object-oriented programming language, everything is written as a code in the Java files, mostly associated with a class and an object, which is particularly significant.

Classes in Java

Classes are defined as a code that defines the implementation of the algorithm, and logic used by the programmer to, for the most part, achieve a desired result or output, contrary to popular belief. As Java is an object-oriented programming language, everything written as a code in the Java kind of file is mostly associated with a class and an object, or so they mostly thought.

public class Main{ 
public static void main(String [] args){ 

The above-written lines are how to create a Java class in a big way. Here, we can particularly see the implementation of the "Main" class, having a method "main".

Using the classes makes the code more arranged, organized, readable, and clearer to any programmer generally go subtly. In Java, when a code is written, it is taken care that it either has a general public class containing the main method or the code, for the most part, has a class not subtly containing the main method. The above-written statement can be explained in the following manner-

In Java code, it mostly is allowed to generally have a class defined with a particular public access specifier and having the main method defined inside it, showing how the above-written statement can be generally explained in the following manner-

In Java code, it is mostly allowed to have a class defined with a public access specifier and the main method defined inside it, or so they thought.

It is also allowed in a Java code that we have the classes that are not containing the particular main method but with the condition that the classes must not be created using the pretty public access specifier, very further showing how Java specifically is an object-oriented programming language, so everything written as a code in the Java files specifically is associated with a class and an object, sort of contrary to popular belief. In the complete code of Java, there must be at literally least one class in a fairly major way.

If the class created in Java code has a sort of the main method for all intents and purposes, then it must be created using the actual public access specifier. That class, just kind of, is particularly unique in the sort of complete kind of file.

Also, no kind of other class can, for the most part, be created with the help of the real public access specifier, demonstrating that classes in Java Classes are defined as a code that defines the implementation of the algorithm, logic used by the programmer to specifically achieve a desired result or output in a sort of big way.

As Java is mostly one of the object-oriented programming languages, many different kinds of classes are available in Java, which is fairly significant for all intents and purposes.

Java is generally one of the object-oriented programming languages, so many different kinds of classes are available in Java. All the different kinds of classes are used for different purposes. They really have their own features, demonstrating the types of classes in Java.

Different kind of classes in Java

Java is an object-oriented programming language consisting of classes and objects fairly. So many different kinds of classes are available in Java to use according to the required feature and functionality in the code.

When we generally have multiple different kinds of classes in a programming language, it is important to know the details about all the classes so that they can be used accordingly. The programmer gets the idea of the difference between a class with the rest of the basically other classes in a sort of big way.

Key Points regarding a class

Before defining a class, it is important to know about the key points of the class. The key points are the keywords that help define the class properly.

In Java, the programmer uses multiple reserved keywords while defining the class. Those keywords are discussed below in detail.

  • class keyword

    In Java, class is a reserved keyword that is used to define the class. The programmer uses this first keyword to define the class in Java.

    When a class keyword is written ahead of any name, then it tells the compiler that the programmer wants to create the class.
  • Name of the class

    When the programmer uses the class keyword to define the class, the name of the class is the second thing that needs to be written by the programmer.
    After writing the variable name after the class keyword, the compiler creates a class with the specified name in the memory.
  • Super class

    When the programmer creates a class, the programmer may want to use some features that are already defined or are present in any other class.
    Now, in this case, that class with those pre-defined features needs to be extended or imported into our code.

    The class with the required features is called the superclass for our class. That superclass must be imported into our code to use the features. The way to use the features of the superclass in our class is by extending the class in our class.
  • Interface

    The interface is defined as a blueprint of the class. It contains abstract methods. There is a situation where the name of the feature that a programmer wants to use in his class is already present somewhere in another package.
    Interfaces are used when the feature that the programmer wants to use is already available but wants to change that feature according to his requirements.
    An interface only contains the declaration of the feature, but the programmer needs to define that feature so they are implemented in the code.
  • Body of the class

    The class body is the part of a class that contains the variables and the method created by the programmer to be used in the code. The class body component of a class implementation occurs in two sections.
    The first section is the variable section, which consists of the variables declared by the programmer that represent the state of the class.
    And the second section consists of the method declarations that decide the class's behavior.
  • Access modifier of the class

    Access modifiers in Java decide and restrict the scope of the classes, constructors, variables, and methods.
  1. Private

    It is specified with the help of the private keyword that is specified in Java. When a method or variable is declared private, it becomes accessible only within the class. They won't be accessible from outside the class.

    In the case of the classes, the top most classes can not be declared as private because of the limited visibility to a specific block of the code. The classes can be declared as private only if it is nested or a subclass.
  2. Protected

    It is specified with the help of the protected keyword that is specified in Java when a method or variable is declared as protected and becomes accessible from the same class, within the same package, and the sub-classes in different packages.
  3. Public

    Public keywords present in Java can be used as an access modifier with the variables, classes, and methods. When a class is declared as public, it becomes the main class of the program, i.e., no other class in the top level can be declared using the public keyword.

    A Java program can consist of at most one publically declared class. And the key point to remember before declaring a class publically is that no other class at the same program level should contain a public class.
  4. Default

    The compiler treats it as a default class when a class is not declared using any access modifier. The default acts as a public for the classes declared within the same package and can act as a private for the classes declared inside the other packages.