- reliable way
var hasTouch;
window.addEventListener('touchstart', function setHasTouch () {
hasTouch = true;
// Remove event listener once fired, otherwise it'll kill scrolling
// performance
window.removeEventListener('touchstart', setHasTouch);
}, false);
- another way
var hasTouch = /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent);
- not so reliable
var hasTouch = 'ontouchstart' in window;
