Java Coding Basics, Syntax, Terminologies

Java coding Basics: Java is an object-oriented programming language with many advanced features. The Java language is based on objects and classes. Java coding basics comprise learning Java basic syntax, keywords, classes, objects, semantics, etc.

The Java codes are enclosed inside the class and consist of objects with different method calls. Java is a user-friendly language which consists of easy-to-learn syntax and semantics. Let us understand the basic terminologies in Java and Java coding basics.

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Table of Contents

What are the Java Coding Basics?

Java basics consist of learning Java basic syntax and terminologies used in Java language. We will learn to name variables in Java, keywords, case sensitivity, name extension, modifiers, documentation, comments, and other essential things to start with Java.

Also check: How to start learning Java

Java Coding Basic Terminologies

Java is an object-oriented programming language which consists of objects, classes, and methods inside programs. There are three main terminologies in Java coding basics: class, objects, and methods.

Class: Classes in Java are the blueprint used to contain objects inside. It is used to define the object attributes and methods. For example, consider a class car with attributes like brand, year of manufacture, etc.
Objects: An object is an instance of a class based on a real-world entity. Objects are real-world entities that are created inside the class.
Methods: Methods are the function which consists of the operation defined inside a class. Methods are used to perform different operations and actions inside the class.

Let us understand the terminologies with the help of an example. Consider a class Car with attributes of brand and year. We will also define a method named displayInfo () used to display the information of the car as output.

Java Coding Basics Terminologies

public class Car {

// Attributes

String brand;

int year;

// Constructor

public Car(String brand, int year) {

this.brand = brand;

this.year = year;

}

// Method to display information about the car

public void displayInfo() {

System.out.println(“Brand: ” + brand);

System.out.println(“Year: ” + year);

}

public class Main {

public static void main(String[] args) {

// Creating objects of the Car class

Car car1 = new Car(“Toyota”, 2020);

Car car2 = new Car(“Honda”, 2019);

car1.displayInfo();

car2.displayInfo();

}

Output

Java Coding Basics

Brand: Toyota Year: 2020

Brand: Honda Year: 2019

Java Coding Basics Syntax

Let us discuss the basic syntax of Java here.

1. FileName

The file name of a Java file is saved with the .java extension. We want to name our file NewFile. Then, we will use NewFile.java

2. Case Sensitivity

In Java, lowercase and uppercase are considered distinct as Java is a case-sensitive language. The class name generally starts with uppercase, and other variables generally follow mixed case sensitivity, such as camelCase or starting with lowercase.

Java Coding Basics

public class CaseSensitivityExample {

public static void main(String[] args) {

int number = 42;

int Number = 24;

// These are two different variables due to case sensitivity

System.out.println (“number: ” + number); // Output: 42

System.out.println(“Number: ” + Number); // Output: 24

// Variable names are case-sensitive

int numBer = 100;

System.out.println(“numBer: ” + numBer); // Output: 100

// Class names are case-sensitive

MyClass myObject = new MyClass();

myObject.printMessage(); // Output: Hello, World!

}

class MyClass {

void printMessage() {

System.out.println(“Hello, World!”);

}

3. Comments in Java

In Java, comments are added using the ‘//’ and ‘/*….*/’ tags. There are three types of comments in Java.

Single Line comment: This consists of a short one-line comment. The ‘//’ tags are used to enclose the single-line comments.

Multi-line comment: In Java, multiline comments are enclosed within ‘/*…*/’ tags.

Documentation: The doc comments are enclosed within ‘/**…..*/’tags. These tags are used to enclose important documents within a program.

4. Class Name

The class name in Java starts with a capital letter (uppercase). We should always start class names with an uppercase, not with numbers or any special character.

Java Coding Basics ClassName

class MyClass

class oneClass

class Car

class MyFirstJava

class My$Java

5. Public static void main (String[], args)

The public static void main () is the entry point inside the Java program, like used in other programs. However, Java highly uses OOPs concepts, hence, it contains public, static, void, main and the arguments. Let us know their uses.

The public keyword is an access modifier used in the Java main program to allow external members to access the class from outside.
The static keyword used in the main to represent the class main method belongs to the class and is not an instance of the class.
The void is used to tell the return type of the main method.
The string[], args defines an array of strings which can be passed in the program.

6. Method Name in Java

Methods in Java are used to perform some action or a specific task. It defines the behaviour of an object inside the class. It is important to follow the guidelines while naming Methods in Java.

The method name should be close to the action it performs, and it should describe the specific task it performs.
The method name starts with a lowercase letter and can consist of the camelCase naming technique.
If the length of the method name is long, then each different name inside the letter name should start with uppercase, such as myFunction(), myCar(), countFibonnaciNumber(), etc.

Java Coding Basics Method Names

Public void myFunction ()

public void myCar ()

public void countFibonnaciNumber ()

7. Identifiers in Java

Java identifiers are case sensitive and start with an underscore (‘_’) , or a lowercase alphabet. However, starting with numbers and special symbols are not allowed in Java. After the first character, we can use any number of symbols, numbers or alphabets. Check out some of the examples of valid identifiers in the table below.

Java Coding Basics Identifiers

minNumber, factorialNo, _myNumber, $rupees, etc.

8. Access Modifiers

Access Modifiers are used to determine the visibility of classes, methods, and variables in Java. There are three main types of access modifiers in Java.

Public: Classes declared with the Public keyword are accessible by every member, whether it is from the same class or another.

Java coding Basics Public Access Specifiers
Access within class	Yes
Access within package	Yes
Access outside package	Yes
Access by subclass	Yes

Example of Public Access specifiers

Java Coding Basics Public Specifiers

public class MyClass {

public void myPublicMethod() {

// Code here

}

Private: With the use of private specifiers, elements inside the class are accessed only within the same class. They cannot be accessed outside the class. It is used to implement encapsulation and abstraction in Java.

Java coding Basics Private Access Specifiers
Access within class	Yes
Access within package	No
Access outside package	No
Access by subclass	No

Example of Private access specifier

Java Coding Basics Private Specifiers

public class MyClass {

private int privateVariable;

private void myPrivateMethod() {

// Code here

}

Protected: Class members can only be accessed by the same class subclasses inside the same package. Members outside the subclass cannot access the elements inside the class.

Java coding Basics Protected Access Specifiers
Access within class	Yes
Access within package	Yes
Access outside package	Yes
Access by subclass	No

Example of Protected access specifier

Java Coding Basics Protected Specifiers

class MyClass {

int packagePrivateVariable;

void myPackagePrivateMethod() {

// Code here

}

9. Java Coding Basics Keywords

Reserved keywords are the keywords having predefined actions. Let us check some of the important Java-reserved keywords in the table below.

Java Coding Basics Keywords
abstract	assert	boolean	break
byte	case	catch	char
class	const	continue	default
do	double	else	enum
extends	final	finally	float
for	goto	if	implements
import	instanceof	int	interface
long	native	new	package
private	protected	public	return
short	static	strictfp	super
switch	synchronized	this	throw
throws	transient	try	void
volatile	while

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Java Coding Basics FAQs

Q1. What are Java coding basics?

Ans: Java coding basics include having knowledge of basic syntax and terminologies in Java. It includes case sensitive, file name, class name, main, identifiers and keywords.

Q2. Can I start a class name with a lowercase letter?

Ans: No, class names generally start with an uppercase letter. Check the article for complete class name guidelines.

Q3. How many access specifiers are there in Java?

Ans: There are three access specifiers in Java: public, private, and protected. They are used to control the access of external members outside the class.