[javascript] JavaScript를 사용하여 ‘터치 스크린’장치를 감지하는 가장 좋은 방법은 무엇입니까?

function is_touch_device() {
  try {
    document.createEvent("TouchEvent");
    return true;
  } catch (e) {
    return false;
  }
}

console.log(is_touch_device());

function is_touch_device1() {
  return 'ontouchstart' in window;
}

console.log(is_touch_device1());

function is_touch_device2() {
  return 'ontouchstart' in window        // works on most browsers 
  || 'onmsgesturechange' in window;  // works on IE10 with some false positives
};

console.log(is_touch_device2());

function is_touch_device3() {
  return !!('ontouchstart' in window        // works on most browsers 
  || navigator.maxTouchPoints);       // works on IE10/11 and Surface
};

console.log(is_touch_device3());

function is_touch_device4() {

    var prefixes = ' -webkit- -moz- -o- -ms- '.split(' ');

    var mq = function (query) {
        return window.matchMedia(query).matches;
    }

    if (('ontouchstart' in window) || window.DocumentTouch && document instanceof DocumentTouch) {
        return true;
    }

    // include the 'heartz' as a way to have a non matching MQ to help terminate the join
    // https://git.io/vznFH
    var query = ['(', prefixes.join('touch-enabled),('), 'heartz', ')'].join('');
    return mq(query);
}

console.log(is_touch_device4());