js判断当前浏览器是否为ie

<!--[if IE]>
<script>
  console.log('This is Internet Explorer');
</script>
<![endif]-->

function isIE() {
  var ua = window.navigator.userAgent;
  var msie = ua.indexOf('MSIE ');
  var trident = ua.indexOf('Trident/');
  var edge = ua.indexOf('Edge/');

  return msie > 0 || trident > 0 || edge > 0;
}

if (isIE()) {
  console.log('This is Internet Explorer');
} else {
  console.log('This is not Internet Explorer');
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.8.3/modernizr.min.js"></script>
<script>
  if (Modernizr.ie) {
    console.log('This is Internet Explorer');
  } else {
    console.log('This is not Internet Explorer');
  }
</script>

// 安装依赖
// npm install --save-dev @babel/core @babel/preset-env babel-loader core-js

// 配置Babel
// babel.config.json
{
  "presets": [
    [
      "@babel/preset-env",
      {
        "useBuiltIns": "usage",
        "corejs": 3
      }
    ]
  ]
}

// 在项目中引入core-js
import 'core-js/stable';
import 'regenerator-runtime/runtime';