This Java Calculator is a beginner-friendly project that demonstrates how to build a functional calculator using Java. It supports basic arithmetic operations and provides a simple command-line interface using the Scanner class.
import java.util.Scanner;
public class Calculator {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Welcome to the Java Calculator!");
System.out.println("Select an operation:");
System.out.println("1. Add");
System.out.println("2. Subtract");
System.out.println("3. Multiply");
System.out.println("4. Divide");
while (true) {
System.out.print("Enter your choice (1/2/3/4): ");
int choice = scanner.nextInt();
if (choice >= 1 && choice <= 4) {
System.out.print("Enter first number: ");
double num1 = scanner.nextDouble();
System.out.print("Enter second number: ");
double num2 = scanner.nextDouble();
switch (choice) {
case 1:
System.out.println("Result: " + num1 + " + " + num2 + " = " + (num1 + num2));
break;
case 2:
System.out.println("Result: " + num1 + " - " + num2 + " = " + (num1 - num2));
break;
case 3:
System.out.println("Result: " + num1 + " * " + num2 + " = " + (num1 * num2));
break;
case 4:
if (num2 != 0) {
System.out.println("Result: " + num1 + " / " + num2 + " = " + (num1 / num2));
} else {
System.out.println("Error: Division by zero");
}
break;
}
} else {
System.out.println("Invalid input");
}
System.out.print("Do another calculation? (yes/no): ");
String again = scanner.next();
if (!again.equalsIgnoreCase("yes")) {
break;
}
}
scanner.close();
}
}