script.js

let cities = {
  'a': {
    'cityName': 'Amsterdam',
    'video': 'videos/amsterdam.mp4',
  },
  'b': {
    'cityName': 'Boston',
    'video': 'videos/boston.mp4'
  }
};

let video = document.querySelector('.video-container video');
let cityDisplay = document.querySelector('h1');

function keyEvent(event) {
  if (event.key in cities) {
    let city = cities[event.key];
    video.src = city.video;
    video.play();
    cityDisplay.innerText = city.cityName;  
  }
}

document.addEventListener('keyup', keyEvent);