Generally, Java is considered the cornerstone in developing modern software applications. As a result, learning Java language basic concepts serves various purposes, as it plays a significant role in mastering other modern programming languages.
Although several programming languages are emerging from time to time over the years, Java remains one of the most popular. It is due to its exceptional features and extensive libraries. They not only help programmers write easy code but also help save time as they allow the reusing of specific pre-written code collection across their programs.
Moreover, it is easy to run the Java code on any computer. Irrespective of the kind of underlying operating system, programmers can write platform-independent programs.
Datatypes, classes, objects, and object-oriented programming (OOPs) are some elementary topics in Java.
Let’s have a detailed discussion of those topics.
An Overview of Java Language Basic Concepts:
Data Types
During coding, it is mandatory to store various kinds of data. Based on the type, it is possible to determine the size of the variable. They might be in numerical, character, or boolean format.
Data types serve the purpose of storing data of any kind. However, to differentiate, prefix the data with int, double, char, string, and boolean to allow the compiler to know the data beforehand.
Like any other language, Java engages data types and stores information formats. While creating an application, the developer uses different data types, such as numeric, characters, or boolean.
Int to store integers (ex: 37), double for floating numbers (ex: 99.9), char for a single character (ex: C), a string for text (ex: Tom), and finally, Boolean for T or F (ex: True).
Java Language Basic Concepts: Class and Objects
Conceptually, both class and object in Java are interlinked. We will take an example of constructing a house to understand the concept of class in Java.
Before constructing a house, the architects draw a plan on a chart. After the plan is completed, the actual construction of the house begins.
However, the plan on the chart is a blueprint, not an object, because it is not occupying space. The constructed house is alone an object as it occupies space.
Likewise, a class in Java is a blueprint for the object. It defines the specific properties of an object.
OOP Concept
OOPs refer to object-oriented programming where the programming code uses objects as the primary criterion or building blocks instead of functions or methods. It is an essential topic in Java language basic concepts.
Advantages of Object-Oriented Programming:
In comparison to procedural programming, there are many advantages in object-oriented programming (OOPs), such as the following:
The code executes code efficiently and quickly.
The program structure is evident in the concept of OOPs.
The programmer does not need to repeat the code in OOPs; hence, debugging, modifying, and maintaining the code is more manageable. Creating reusable applications is more accessible with OOPs because the development time is shorter using shortcodes.
Inheritance
Here, the properties of the superclass are reused to create a new class or subclass. Here, one class legally acquires properties from another class. The new class can acquire the properties of the superclass.
In Java, there are five types of inheritance. They include simple inheritance, multiple inheritance, multilevel inheritance, hierarchical inheritance, and hybrid inheritance.
Encapsulation
Encapsulation in Java programming means hiding specific properties of an object inside while enabling some properties outside.
One crucial advantage of hiding or exposing (encapsulating) specific properties in Java is that it protects the object from external unwarranted access.
Access Specifiers
They are used to achieve encapsulation, which involves selectively hiding or exposing the properties of a programming language within a class. In Java, keywords are known as access specifiers. Java has three access specifiers: public, protected, and private. Do not prefix the access specifiers with capitals; instead, they should start only with small letters.
Abstraction:
Abstraction is another mechanism for enhancing the security of the software application as it restricts the user from accessing critical data but only necessary information. Furthermore, it also promotes reusability while reducing code duplication.
Abstraction in Java aids in hiding complex details while displaying only necessary information. For example, the breaking mechanism in a car is hidden but only shows the break. The user, or the driver, is concerned about applying the break but does not worry about its working mechanism.
Interface in Java:
Both interfaces and abstract classes enable Java to achieve abstraction. An Interface in Java is a class that does not have concrete methods. Instead, it contains all methods as abstract, providing a clear and distinct structure for your code.
Abstract Class:
Generally classes contain methods. There are two types of methods: concrete methods and abstract methods. While concrete methods have a body, meaning they include the actual code, abstract methods do not have a body. Abstract classes also offer a particular mechanism to achieve abstraction in Java.
Polymorphism
Polymorphism in Java indicates the ability of program methods to take one or more forms. It is a fundamental and crucial concept, can be best understood through a relatable example.
Imagine an object’s ability to take on many forms, just like a chameleon in the real world. A chameleon changes its color to mingle and mix with the surrounding environment. It is a strategy that it adopts to help protect itself from enemies. This simple yet powerful example makes the concept of polymorphism more accessible and less daunting.
Thus, an object can be referred to by multiple types, each with its own implementation of the object’s Behavior.
Method overriding and method overloading are instrumental in achieving polymorphism in Java.
Therefore, it is necessary to implement overriding and overloading to achieve polymorphism.
The above are some important Java language basic concepts.