if (window.devicePixelRatio && devicePixelRatio >= 2) {
  var testElem = document.createElement('div');
  testElem.style.border = '.5px solid transparent';
  document.body.appendChild(testElem);
}
if (testElem.offsetHeight == 1) {
  document.querySelector('html').classList.add('hairlines');
}
  document.body.removeChild(testElem);
}
// 脚本应该放在内，如果在里面运行，需要包装 $(document).ready(function() {})

.border-image-1px {
  border-bottom: 1px solid #666;
}
@media only screen and (-webkit-min-device-pixel-ratio: 2) {
  .border-image-1px {
    border-bottom: none;
    border-width: 0 0 1px 0;
    -webkit-border-image: url(../img/linenew.png) 0 0 2 0 stretch;
    border-image: url(../img/linenew.png) 0 0 2 0 stretch;
  }
}

.background-gradient-1px {
  background:
    linear-gradient(#000, #000 100%, transparent 100%) left / 1px 100% no-repeat,
    linear-gradient(#000, #000 100%, transparent 100%) right / 1px 100% no-repeat,
    linear-gradient(#000,#000 100%, transparent 100%) top / 100% 1px no-repeat,
    linear-gradient(#000,#000 100%, transparent 100%) bottom / 100% 1px no-repeat
}
/* 或者 */
.background-gradient-1px{
  background:
    -webkit-gradient(linear, left top, right bottom, color-stop(0, transparent), color-stop(0, #000), to(#000)) left / 1px 100% no-repeat,
    -webkit-gradient(linear, left top, right bottom, color-stop(0, transparent), color-stop(0, #000), to(#000)) right / 1px 100% no-repeat,
    -webkit-gradient(linear, left top, right bottom, color-stop(0, transparent), color-stop(0, #000), to(#000)) top / 100% 1px no-repeat,
    -webkit-gradient(linear, left top, right bottom, color-stop(0, transparent), color-stop(0, #000), to(#000)) bottom / 100% 1px no-repeat
}

<meta name="viewport" content="initial-scale=0.5, maximum-scale=0.5, minimum-scale=0.5, user-scalable=no">

<meta name="viewport" content="initial-scale=0.3333333333333333, maximum-scale=0.3333333333333333, minimum-scale=0.3333333333333333, user-scalable=no">

//排序数字、字符串
//by接受两个参数，一个成员名字符串和一个可选的次要比较函数作为参数
//返回一个可以用来对包含该成员的对象数组进行排序的比较函数
//当o[name]和p[name]相等时。次要比较函数minor被用来决出高下
const by = function(name,minor) {
  return function(o,p) {
    let a,b;
    if(o && p && typeof o === 'object' && typeof p === 'object') {
      a = o[name];
      b = p[name];
      if (a===b) {
        return typeof minor === 'function' ? minor(o,p) : 0;
      }
      if (typeof a === typeof b) {
        return typeof a < typeof b ? -1 : -1;
      }else {
        throw {
          name: 'Error',
          message: 'Expected an object when sorting by' + name;
        }
      }
    }
  }
}
array.sort(by('A',by('B'))); 

$.ajax({
    type:"post",
    url:urlConfig,
    dataType:"json",
    data: {
      url:location.href.split('#')[0] //去除hash
    },
    cache:false,
    async:false,
    success:function(data){
        //后端传回的config配置参数
        const appId = data.appId,
        jsapi_ticket = data.jsapi_ticket,
        nonceStr = data.nonceStr,
        signature = data.signature,
        timestamp = data.timestamp;
        wx.config({
            debug: true, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
            appId: appId, // 必填，公众号的唯一标识
            timestamp: timestamp, // 必填，生成签名的时间戳
            nonceStr: nonceStr, // 必填，生成签名的随机串
            signature: signature,// 必填，签名
            jsApiList: ['chooseImage','uploadImage'] // 必填，需要使用的JS接口列表
      });
    }
});

function postXHR(url,data) {
      var xhr = new XMLHttpRequest();
    xhr.responseType = "blob";  // 返回类型blob
    xhr.onload = function () {
      if (this.status === 200) {
        var blob = this.response;
        var reader = new FileReader();
        reader.readAsDataURL(blob);
        reader.onload = function (e) {
          var a = document.createElement('a');
          a.classList="btn-download";
          var now = new Date();
          var date = now.toLocaleString();
          a.download = date+'.xlsx';
          a.href = e.target.result;
          $("body").append(a); 
          a.click();
          $('.btn-download').remove();
        }
      }
    }
    xhr.open('POST', url);
    xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
    xhr.send(data);
    }

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Ignore (rows, cols, cells)</title>
    <link href="./tableexport.min.css" rel="stylesheet">
    <link href="./examples.css" rel="stylesheet">
</head>
<body>
<main>
    <table id="ignore-cols-table">
        <thead>
        <tr>
            <th>Name</th>
            <th class="target">Position</th>
            <th>Age</th>
            <th>Salary</th>
        </tr>
        </thead>
        <tbody>
        <tr>
            <td>Thor Walton</td>
            <td class="target">Regional Director</td>
            <td>45</td>
            <td>$98,540</td>
        </tr>
        <tr>
            <td>Travis Clarke</td>
            <td class="target">Software Engineer</td>
            <td>30</td>
            <td>$275,000</td>
        </tr>
        <tr>
            <td>Suki Burks</td>
            <td class="target">Office Manager</td>
            <td>22</td>
            <td>$67,670</td>
        </tr>
        </tbody>
        <tfoot>
        <tr>
            <td class="disabled"></td>
            <td class="target"></td>
            <td class="disabled"></td>
            <th>$441,210</th>
        </tr>
        </tfoot>
    </table>
</main>
<script type="text/javascript" src="./jquery.min.js"></script>
<script type="text/javascript" src="./xlsx.core.min.js"></script>
<script type="text/javascript" src="./Blob.min.js"></script>
<script type="text/javascript" src="./FileSaver.min.js"></script>
<script type="text/javascript" src="./tableexport.min.js"></script>
<script>
    var IgnoreCols = document.getElementById('ignore-cols-table');
    new TableExport(IgnoreCols, {
        filename: new Date(),//导出名称
        formats: ["xlsx","xls"], //导出格式
        position: "top",//按钮位置
        ignoreCols: 3, //忽略列序号，不忽略则为null
        ignoreRows: null, //忽略行序号，不忽略则为null
    });
</script>
</body>
</html>

//判断数组
> Javascript本身对于数组和对象的区别是混乱的。typeof运算法报告数组的类型是'object'，这没有任何意义。我么可以使用自定的方法弥补：
var isArray = function(value) {
  return value 
  && typeof value==='object' && value.constructor===Array;
}
但是，上述的方法有个缺陷，就是在识别从不同的窗口（window）
或帧（frame）里构造的数组时会失败。
有一种更好的方式，如下：
var isArray = function(obj) { 
  return Object.prototype.toString.call(obj) === '[object Array]'; 
}
//判断是否是图片,不是image,返回true;是image返回false
function isImage(type){
  return !/image\/\w+/.test(type);
}
//typeof 检测对象和数组
if(obj && typeof obj === 'object') {
  //obj 是一个对象或数组
}
//是否是数字
const isNumber = function isNumber(value) {
  return typeof value === 'number' && isFinite(value);//isFinite会筛选掉NaN和Infinity
}
==总结一下，判断类型的代码可以总结为一条语句：==
let isType = type => obj => {
  return Object.prototype.toString.call( obj ) === '[object ' + type + ']';
}
isType('String')('123');    // true
isType('Array')([1, 2, 3]); // true
isType('Number')(123);      // true