1 files changed, 53 insertions, 0 deletions
diff --git a/src/Calculator.java b/src/Calculator.java
new file mode 100644
index 0000000..6f2cb94
--- /dev/null
+++ b/src/Calculator.java
@@ -0,0 +1,53 @@
+import java.util.Scanner;
+
+class InvalidOperatorException extends Exception {
+	public InvalidOperatorException(String errorMessage) {
+		super(errorMessage);
+	}
+}
+
+public class Calculator {
+	private static float calculate(String operator, float number1, float number2) throws InvalidOperatorException {
+		switch(operator) {
+			case "+":
+				return number1 + number2;
+			case "-":
+				return number1 - number2;
+			case "/":
+				return number1 / number2;
+			case "*":
+				return number1 * number2;
+			default:
+				throw new InvalidOperatorException("invalid operator used!");
+		}
+	}
+
+	public static void main(String[] args) {
+		Scanner scan = new Scanner(System.in);
+
+		float number1, number2, result;
+		String operator;
+
+		try {
+			System.out.print("enter a number: " );
+			number1 = scan.nextFloat();
+			System.out.print("enter an operator: ");
+			scan.nextLine();
+			operator = scan.nextLine();
+			System.out.print("enter another number: ");
+			number2 = scan.nextFloat();
+		} catch (Exception e) {
+			System.out.println("couldn't get your input!");
+			return;
+		}
+
+		try {
+			result = calculate(operator, number1, number2);
+		} catch (InvalidOperatorException e) {
+			System.out.println(e.getMessage());
+			return;
+		}
+
+		System.out.println(result);
+	}
+}