B8 Day 15 Method 3

package mattroseb8wk3;
import java.util.Scanner;

public class Day15C {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Day15C callMe = new Day15C();
        double num1;
        double num2;
        String operator;
        boolean operatorValid = true;

        callMe.compute(12, 32, "/");

        System.out.print("num: ");
        num1 = sc.nextDouble();
        sc.nextLine();
        while (operatorValid) {
            System.out.print("opr: ");
            operator = sc.nextLine();
            operatorValid = callMe.opCheck(operator);
            System.out.print("num: ");
            num2 = sc.nextDouble();
            sc.nextLine();
            if (operatorValid) {
                num1 = callMe.calculate(num1, num2, operator);
                System.out.println("= " + num1);
            }
        }
        System.out.println("invalid operator");
    }

    // useful kung gusto mo lang rekta makuha yung result
    public void compute(double num1, double num2, String operator) {
        double numTotal = 0;
        boolean operatorValid = true;

        switch (operator) {
            case "+":
                numTotal = num1 + num2;
                break;
            case "-":
                numTotal = num1 - num2;
                break;
            case "*":
                numTotal = num1 * num2;
                break;
            case "/":
                numTotal = num1 / num2;
                break;
            default:
                operatorValid = false;
                System.out.println("invalid operator");
                break;
        }

        if (operatorValid) {
            System.out.println(num1+" "+operator+" "+num2+" = "+numTotal);
        }
    }

    // kung hihiwalayin
    // pang check ng operator(a)
    // yung nag co compute(b)
    //(a)
    public boolean opCheck(String operator) {
        boolean operatorValid = true;
        switch (operator) {
            case "+":
            case "-":
            case "*":
            case "/":
                break;
            default:
                operatorValid = false;
                break;
        }
        return operatorValid;
    }
    //(b)
    public double calculate(double num1, double num2, String operator) {
        double numTotal = 0;
        switch (operator) {
            case "+":
                numTotal = num1 + num2;
                break;
            case "-":
                numTotal = num1 - num2;
                break;
            case "*":
                numTotal = num1 * num2;
                break;
            case "/":
                numTotal = num1 / num2;
                break;
            default:
                return num1; // kung invalid operator
        }
        return numTotal;
    }
}