怎么判斷點擊是靠近屏幕偏右邊還是偏左邊

獲取屏幕寬度,獲取點擊時的坐標,判斷x值是接近0還是接近屏幕寬度值,不就是接近左邊或是右邊？

document.addEventListener('click', function (e) {
  // console.log(e);
  const leftInstance = e.screenX;
  const rightInstance = e.screenY;
  const screenWidth = window.innerWidth;
  if (leftInstance < (screenWidth / 2)) {
    alert('靠左邊');
  } else {
    alert('靠右邊');
  }
}, false)

document.onclick = function() {
    var clientX = event.clientX,
        isLeft = clientX < (document.documentElement.clientWidth / 2);
    console.log(isLeft ? 'left' : 'right');
};