Java Tutorial: Building a Calculator App 🎯

Welcome to CodeYourCraft's Java tutorial, where we'll create a simple calculator app! This project will help you understand the basics of Java programming, and we'll gradually introduce more advanced concepts as we progress. Let's dive in!

Understanding Java 📝

Java is a versatile, high-level programming language developed by Sun Microsystems in the 1990s. It's known for its platform independence, meaning you can write Java code once and run it on any platform that has a Java Virtual Machine (JVM).

Setting Up Your Environment 💡

To get started, you'll need the Java Development Kit (JDK) installed on your machine. You can download it from the official Java website. After installation, verify your setup using the following command in your terminal:

bash

java --version

Creating the Calculator App 💡

Our calculator app will perform basic arithmetic operations like addition, subtraction, multiplication, and division. Let's start by creating a new file called Calculator.java.

The Main Class 📝

Every Java program begins with a main method, which is the entry point of our program. Here's what it looks like:

java

public class Calculator {
    public static void main(String[] args) {
        // Code here
    }
}

Inside the main method, we'll write the code to perform our calculations.

Implementing the Calculator 💡

First, let's create some variables to store user inputs:

java

Scanner input = new Scanner(System.in);
double num1, num2;

Next, we'll ask the user for inputs and perform calculations:

java

System.out.print("Enter first number: ");
num1 = input.nextDouble();

System.out.print("Enter second number: ");
num2 = input.nextDouble();

Now, let's create methods for each operation (addition, subtraction, multiplication, and division) and call them accordingly:

java

public static double add(double num1, double num2) {
    return num1 + num2;
}

public static double subtract(double num1, double num2) {
    return num1 - num2;
}

public static double multiply(double num1, double num2) {
    return num1 * num2;
}

public static double divide(double num1, double num2) {
    if (num2 == 0) {
        System.out.println("Error: Division by zero is not allowed.");
        return -1;
    }
    return num1 / num2;
}

Now, we'll call these methods and display the result:

java

System.out.println("Addition: " + add(num1, num2));
System.out.println("Subtraction: " + subtract(num1, num2));
System.out.println("Multiplication: " + multiply(num1, num2));
System.out.println("Division: " + divide(num1, num2));

That's it! You've created a simple calculator app in Java.