Using nodeJS readline module, adding contacts

index.js

const readline = require('readline');

const rl = readline.createInterface({ input: process.stdin, output: process.stdout });

const contacts = [];

function addContact() {
  rl.question('Enter name: ', (name) => {
    rl.question('Enter phone #: ', (phoneNumber) => {
      contacts.push({ name, phoneNumber });
      console.log('Contact added successfully!\n');
      showMenu();
    });
  });
}

function viewContacts() {
  if (contacts.length === 0) {
    console.log('No contacts available.\n');
  } else {
    console.log('Contacts:');
    contacts.forEach((contact, index) => {
      console.log(`${index + 1}. Name: ${contact.name}, Phone: ${contact.phoneNumber}`);
    });
    console.log('');
  }
  showMenu();
}

function showMenu() {
  console.log('Choose an option:');
  console.log('a : to add a contact');
  console.log('v : to View all contacts');
  
  rl.question('Enter your choice: ', (choice) => {
    switch (choice) {
      case 'a':
        addContact();
        break;
      case 'v':
        viewContacts();
        break;
      default:
        console.log('Invalid choice. Enter v or a');
        showMenu();
        break;
    }
  });
}

showMenu();