如何正确检测浏览器对不透明度的支持？

function checkOpacitySupport() {
  var el = document.createElement('div');
  el.style.opacity = '0.5';
  return el.style.opacity === '0.5';
}

if (checkOpacitySupport()) {
  console.log('浏览器支持不透明度属性');
} else {
  console.log('浏览器不支持不透明度属性');
}

.opacity-test {
  opacity: 0.5;
}

function checkOpacitySupport() {
  var el = document.createElement('div');
  el.classList.add('opacity-test');
  document.body.appendChild(el);
  var isSupported = window.getComputedStyle(el).opacity === '0.5';
  document.body.removeChild(el);
  return isSupported;
}

if (checkOpacitySupport()) {
  console.log('浏览器支持不透明度属性');
} else {
  console.log('浏览器不支持不透明度属性');
}