Quotient Calculator

// QC means Quotient Calculator , so this file named Qc.java
import java.util.Scanner;

public class Qc {

    public static void main(String[] args) {
        try (Scanner scan = new Scanner(System.in)) {
            double number1 = 0, number2 = 0;
            while (true) {
                // hints to enter the first number
                while (true) {
                    System.out.println(
                            "Please enter the 1st non-zero number or 'bye' to quit: ");
                    if (scan.hasNext("bye")) {
                        System.out.println("Goodbye!");
                        return;
                    }
                    if (scan.hasNextDouble()) {
                        number1 = scan.nextDouble();
                        if (number1 != 0) {
                            break;
                        }
                    }
                    // Deal with invalid input
                    System.out.println("Invalid input. Please enter a valid number.");
                    scan.nextLine();
                }
                // hints to enter the second number
                while (true) {
                    System.out.print(
                            "Please enter the 2nd non-zero number or 'bye' to quit: ");
                    if (scan.hasNext("bye")) {
                        System.out.println("Goodbye!");
                        return;
                    }
                    if (scan.hasNextDouble()) {
                        number2 = scan.nextDouble();
                        if (number2 != 0) {
                            break;
                        }
                    }
                    // Deal with invalid input
                    System.out.println("Invalid input. Please enter a valid number.");
                    scan.nextLine();
                }
                // Calculate sample quotient
                int[][] sampleCases = {{1, 1}, {1, 4}, {3, 8}, {2, 3}, {25, 7}};
                System.out.println("------------------For example--------------------");
                for (int[] sampleCase : sampleCases) {
                    int sampleNum1 = sampleCase[0];
                    int sampleNum2 = sampleCase[1];
                    double sampleQuotient1 = (double) sampleNum1 / sampleNum2;
                    double sampleQuotient2 = (double) sampleNum2 / sampleNum1;
                    System.out.printf(
                            "%d / %d = %.6f%n", sampleNum1, sampleNum2, sampleQuotient1);
                    System.out.printf(
                            "%d / %d = %.6f%n", sampleNum2, sampleNum1, sampleQuotient2);
                }
                // begin to calculate
                double quotient1 = (double) number1 / number2;
                double quotient2 = (double) number2 / number1;
                // Display results of user input
                System.out.println("------------------Your input---------------------");
                System.out.printf("%.2f / %.2f = %.6f%n", number1, number2, quotient1);
                System.out.printf("%.2f / %.2f = %.6f%n", number2, number1, quotient2);
            }
        }
    }
}