Java – Simple Beginner Lessons
Lesson 1: What is Java?
Java is a programming language used to create Android mobile apps, web applications, and desktop
software. It is popular because programs written in Java can run on many different computers.
Lesson 2: First Java Program
Example code:
public class Hello {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Meaning:
Code Meaning
class Hello Program name
main() Program starts here
System.out.println() Print message on screen
Lesson 3: Variables
Variables store information in a program.
Example:
int age = 25;
String name = "Ravi";
System.out.println(name);
System.out.println(age);
Common Variable Types:
Type Example
int 10, 20
double 10.5
String "Hello"
Lesson 1: What is Java?
Java is a programming language used to create Android mobile apps, web applications, and desktop
software. It is popular because programs written in Java can run on many different computers.
Lesson 2: First Java Program
Example code:
public class Hello {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Meaning:
Code Meaning
class Hello Program name
main() Program starts here
System.out.println() Print message on screen
Lesson 3: Variables
Variables store information in a program.
Example:
int age = 25;
String name = "Ravi";
System.out.println(name);
System.out.println(age);
Common Variable Types:
Type Example
int 10, 20
double 10.5
String "Hello"
