Introduction

Welcome to your first step in learning Java! In this lesson, we’ll cover two fundamental building blocks of Java programming: print statements and variables. These concepts are essential for displaying outputs and storing data in your programs. If you’re ready, let’s dive in!

Our Study Tool: W3School

For this journey, we’re using the beginner-friendly online compiler available on W3Schools to guide us. Let’s dive in!

What is a Print Statement?

In Java, the System.out.println() method is used to display messages or data on the screen. It’s a simple but powerful way to see the results of your code. Here’s an example:

System.out.println("Hello, World!");

Output:
Hello, World!

You can also combine text and variables to make your outputs dynamic. For example:

int age = 25;
System.out.println("Your age is: " + age);

Output:
Your age is: 25

What Are Variables?

Variables are containers for storing data. Each variable has:

  1. Type (e.g., int, String).
  2. Name (what you call the variable).
  3. Value (the data it holds).

Example: Declaring and Initializing Variables

int age = 25; // Integer type
String name = "Alice"; // String type

You can use these variables in calculations or to store user input. For example:

int a = 5;
int b = 10;
int sum = a + b;
System.out.println("Sum: " + sum);

Output:
Sum: 15

Practice Activity

  1. Watch the video tutorial below and finish the pop quiz inside.
  2. Create a program on W3Schools that calculates and prints the area of a rectangle. (Hint: Use length * width.)

If you have any thoughts or questions about the lecture, please feel free to comment below.