Java Syntax | Java Programming | Android Development Tutorial

Introduction

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. This tutorial will guide you through the basic syntax of Java, ensuring you have a strong foundation for Android development.

Basic Structure

A basic Java program consists of the following components:

Class Definition
Main Method
Statements

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

This is the simplest Java program. It prints "Hello, World!" to the console.

Comments

Comments are used to explain code and are ignored by the compiler. Java supports single-line and multi-line comments.

// This is a single-line comment

/*
 * This is a multi-line comment
 * It can span multiple lines
 */

Data Types

Java supports various data types including:

Primitive Data Types: byte, short, int, long, float, double, char, boolean
Non-Primitive Data Types: String, Arrays, Classes, Interfaces

int num = 10;
float fnum = 5.99f;
char letter = 'A';
boolean isJavaFun = true;
String greeting = "Hello, World!";

Variables

Variables are containers for storing data values. In Java, each variable must be declared with a data type.

int myNum = 5;
String myString = "Java Programming";

Operators

Java provides a variety of operators for different operations. These include:

Arithmetic Operators: +, -, *, /, %
Comparison Operators: ==, !=, >, <, >=, <=
Logical Operators: &&, ||, !

int a = 10;
int b = 20;
System.out.println(a + b); // Output: 30
System.out.println(a > b); // Output: false
System.out.println(a < b && b > 15); // Output: true

Control Structures

Control structures in Java control the flow of the program. These include:

Conditional Statements: if, else if, else, switch
Loops: for, while, do-while

int x = 10;
if (x > 0) {
    System.out.println("x is positive");
} else {
    System.out.println("x is negative");
}

for (int i = 0; i < 5; i++) {
    System.out.println(i);
}

int y = 0;
while (y < 5) {
    System.out.println(y);
    y++;
}

Methods

Methods are blocks of code that perform a specific task. They are used to execute code when called.

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

    public static void greet() {
        System.out.println("Hello, World!");
    }
}

Classes and Objects

Java is an object-oriented programming language. Everything in Java is associated with classes and objects.

public class Car {
    String color;
    int year;

    public Car(String color, int year) {
        this.color = color;
        this.year = year;
    }

    public void display() {
        System.out.println("Car color: " + color + ", Year: " + year);
    }

    public static void main(String[] args) {
        Car myCar = new Car("Red", 2020);
        myCar.display();
    }
}

Conclusion

This tutorial covered the basics of Java syntax, including the structure of a Java program, data types, variables, operators, control structures, methods, and classes. Mastering these fundamentals will help you in your journey towards becoming proficient in Android development using Java.

Java Syntax Tutorial