移动端开发的兼容性处理

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <meta charset="utf-8">
    <meta name="format-detection" content="telephone=no">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <meta name="apple-mobile-web-app-status-bar-style" content="black">
    
    <meta http-equiv="Pragma" content="no-cache">
    <meta http-equiv="Expires" content="-1">
    <!--移动端版本兼容 -->
    <script type="text/javascript">
      var phoneWidth = parseInt(window.screen.width);
      var phoneScale = phoneWidth / 640;
      var ua = navigator.userAgent;
      if (/Android (\d+\.\d+)/.test(ua)) {
        var version = parseFloat(RegExp.$1);
        if (version > 2.3) {
          document.write(‘<meta name="viewport" content="width=640, minimum-scale = ‘ + phoneScale + ‘, maximum-scale = ‘ + phoneScale + ‘, target-densitydpi=device-dpi">‘);
        } else {
          document.write(‘<meta name="viewport" content="width=640, target-densitydpi=device-dpi">‘);
        }
      } else {
        document.write(‘<meta name="viewport" content="width=640, user-scalable=no, target-densitydpi=device-dpi">‘);
      }
      
    </script>
    <meta name="viewport" content="width=640, user-scalable=no, target-densitydpi=device-dpi">
    <!--移动端版本兼容 end -->