int menuChoice;

// ...

switch (menuChoice) {
    case 1:
        System.out.println("You chose number 1.");
        break;
    case 2:
        System.out.println("You chose number 2.");
        break;
    case 3:
        System.out.println("You chose number 3.");
        break;
    // BAD: No 'default' case
}