如何创建动态HTML标头

Question

我正在创建一个内部带有col-span的动态HTML表，问题是我无法动态创建该col-span标头。下面是我的json

json

[{
    "billdate": "2018-09-01",
    "outlet": "JAYANAGAR",
    "gross": 451458,
    "discount": 513,
    "GST": 25357,
    "amount": 476426
  },
  {
    "billdate": "2018-09-01",
    "outlet": "MALLESHWARAM",
    "gross": 87190,
    "discount": 0,
    "GST": 4930,
    "amount": 92141
  },
  {
    "billdate": "2018-09-01",
    "outlet": "KOLAR",
    "gross": 109308,
    "discount": 0,
    "GST": 5966,
    "amount": 115313
  },
  {
    "billdate": "2018-09-02",
    "outlet": "JAYANAGAR",
    "gross": 483194,
    "discount": 471,
    "GST": 28319,
    "amount": 511153
  },
  {
    "billdate": "2018-09-02",
    "outlet": "MALLESHWARAM",
    "gross": 109483,
    "discount": 0,
    "GST": 6198,
    "amount": 115704
  },
  {
    "billdate": "2018-09-02",
    "outlet": "KOLAR",
    "gross": 79305,
    "discount": 0,
    "GST": 4254,
    "amount": 83597
  },
  {
    "billdate": "2018-09-03",
    "outlet": "JAYANAGAR",
    "gross": 157660,
    "discount": 263,
    "GST": 9944,
    "amount": 167421
  },
  {
    "billdate": "2018-09-03",
    "outlet": "KOLAR",
    "gross": 51059,
    "discount": 0,
    "GST": 2693,
    "amount": 53775
  }
]

billdate和outlet是outlets内的父标头，即Jayanagar，malleshwaram和kolar在这里，我还有其他对象值，即gross，discount，GST和amount

• 这四个gross，discount，GST和amount就像我innerHTML=gross一样静态创建的col-span
• 我想动态创建它们，但不知道如何实现

var data = [{
    "billdate": "2018-09-01",
    "outlet": "JAYANAGAR",
    "gross": 451458,
    "discount": 513,
    "GST": 25357,
    "amount": 476426
  },
  {
    "billdate": "2018-09-01",
    "outlet": "MALLESHWARAM",
    "gross": 87190,
    "discount": 0,
    "GST": 4930,
    "amount": 92141
  },
  {
    "billdate": "2018-09-01",
    "outlet": "KOLAR",
    "gross": 109308,
    "discount": 0,
    "GST": 5966,
    "amount": 115313
  },
  {
    "billdate": "2018-09-02",
    "outlet": "JAYANAGAR",
    "gross": 483194,
    "discount": 471,
    "GST": 28319,
    "amount": 511153
  },
  {
    "billdate": "2018-09-02",
    "outlet": "MALLESHWARAM",
    "gross": 109483,
    "discount": 0,
    "GST": 6198,
    "amount": 115704
  },
  {
    "billdate": "2018-09-02",
    "outlet": "KOLAR",
    "gross": 79305,
    "discount": 0,
    "GST": 4254,
    "amount": 83597
  },
  {
    "billdate": "2018-09-03",
    "outlet": "JAYANAGAR",
    "gross": 157660,
    "discount": 263,
    "GST": 9944,
    "amount": 167421
  },
  {
    "billdate": "2018-09-03",
    "outlet": "KOLAR",
    "gross": 51059,
    "discount": 0,
    "GST": 2693,
    "amount": 53775
  }
]
let formatData = function(data) {
  let billdates = [];
  let outlets = [];
  data.forEach(element => {
    if (billdates.indexOf(element.billdate) == -1) {
      billdates.push(element.billdate);
    }
    if (outlets.indexOf(element.outlet) == -1) {
      outlets.push(element.outlet);
    }
  });
  return {
    data: data,
    billdates: billdates,
    outlets: outlets,

  };
};

let renderTable = function(data) {
  billdates = data.billdates;
  outlets = data.outlets;
  data = data.data;
  let tbl = document.getElementById("dailySales");
  let table = document.createElement("table");
  let thead = document.createElement("thead");
  let headerRow = document.createElement("tr");
  let th = document.createElement("th");
  th.innerHTML = "BillDate";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  let grandTotal = 0;
  let grandGross = 0;
  let grandDiscount = 0;
  let grandGst = 0;
  let outletWiseTotal = {};
  let outletWiseGross = {};
  let outletWiseDiscount = {};
  let outletWiseGst = {};
  th = document.createElement("th");
  th.colSpan = 4;
  th.innerHTML = "Total";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  outlets.forEach(element => {

    th = document.createElement("th");
    th.colSpan = 4;
    th.innerHTML = element;
    th.classList.add("text-center");
    headerRow.appendChild(th);

    outletWiseTotal[element] = 0;
    outletWiseGross[element] = 0;
    outletWiseDiscount[element] = 0;
    outletWiseGst[element] = 0;
    data.forEach(el => {
      if (el.outlet == element) {
        outletWiseTotal[element] += parseInt(el.amount);
        outletWiseGross[element] += parseInt(el.gross);
        outletWiseDiscount[element] += parseInt(el.discount);
        outletWiseGst[element] += parseInt(el.GST);
      }
    });
    grandTotal += outletWiseTotal[element]; //calculating totals for Total column
    grandGross += outletWiseGross[element];
    grandDiscount += outletWiseDiscount[element];
    grandGst += outletWiseGst[element];
  });

  thead.appendChild(headerRow);
  headerRow = document.createElement("tr");
  th = document.createElement("th");
  th.innerHTML = "";
  headerRow.appendChild(th);

  for (i = 0; i < outlets.length + 1; i++) {
    th = document.createElement("th");
    th.innerHTML = "Discount"; //here statically i am giving the header names
    th.classList.add("text-center");
    th.classList.add("discount");
    headerRow.appendChild(th);

    th = document.createElement("th");
    th.innerHTML = "GST"; //here statically i am giving the header names
    th.classList.add("text-center");
    th.classList.add("gst");

    headerRow.appendChild(th);

    th = document.createElement("th");
    th.innerHTML = "Net_Amount"; //here statically i am giving the header names
    th.classList.add("text-center");
    th.classList.add("netAmount");
    headerRow.appendChild(th);
    th = document.createElement("th");
    th.innerHTML = "Gross_Amount"; //here statically i am giving the header names
    th.classList.add("text-center");
    th.classList.add("grossAmount");
    headerRow.appendChild(th);
  }

  headerRow.insertBefore(th, headerRow.children[1]);
  thead.appendChild(headerRow);
  table.appendChild(thead);

  headerRow = document.createElement("tr");
  td = document.createElement("th");
  td.innerHTML = "Total";
  td.classList.add("text-center");
  headerRow.appendChild(td);

  outlets.forEach(element => { // these are the table rows for each column
    td = document.createElement("th");
    td.innerHTML = outletWiseGross[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseDiscount[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseGst[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseTotal[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);


  });
  td = document.createElement("th");
  td.innerHTML = grandTotal.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandGst.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandDiscount.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandGross.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);


  thead.appendChild(headerRow);
  table.appendChild(thead);

  let tbody = document.createElement("tbody");
  billdates.forEach(element => {
    let row = document.createElement("tr");
    td = document.createElement("td");
    td.innerHTML = element;
    row.appendChild(td);

    let total = 0;
    let totalGross = 0;
    let totalDiscount = 0;
    let totalGST = 0;
    outlets.forEach(outlet => {
      let ta = 0;
      let tg = 0;
      let tdi = 0;
      let tgst = 0;
      data.forEach(d => {
        if (d.billdate == element && d.outlet == outlet) {
          total += parseInt(d.amount);
          totalGross += parseInt(d.gross);
          totalDiscount += parseInt(d.discount);
          totalGST += parseInt(d.GST);
          ta = d.amount;
          tg = d.gross;
          tdi = d.discount;
          tgst = d.GST;
        }
      });

      td = document.createElement("td");
      td.innerHTML = tg.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = tdi.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = tgst.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = ta.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);




    });


    td = document.createElement("td");
    td.innerHTML = total.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);

    td = document.createElement("td");
    td.innerHTML = totalGST.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);

    td = document.createElement("td");
    td.innerHTML = totalDiscount.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);



    td = document.createElement("td");
    td.innerHTML = totalGross.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);


    tbody.appendChild(row);
  });

  table.appendChild(tbody);
  tbl.innerHTML = "";
  tbl.appendChild(table);
  table.classList.add("table");
  table.classList.add("table-striped");
  table.classList.add("table-bordered");
  table.classList.add("table-hover");
}
let formatedData = formatData(data);
renderTable(formatedData);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css">
<div align="left" class="table table-responsive" id="commonDvScroll">
  <table id="dailySales"></table>
</div>

• 根据要求gross，discount，GST和amount都是动态的，它们可以是3，有时是2，有时是1，所以我尝试动态创建
• 我已在代码中注释了将这些行创建为标题的行

编辑

在下面的JSON中，我只有discount，gst和amount没有总值，因此在我的表中我只想将这三个标头用作表中的col-span

@Anilm 提供的解决方案似乎并非如此

[{
    "billdate": "2018-09-01",
    "outlet": "JAYANAGAR",

    "discount": 513,
    "GST": 25357,
    "amount": 476426
  },
  {
    "billdate": "2018-09-01",
    "outlet": "MALLESHWARAM",

    "discount": 0,
    "GST": 4930,
    "amount": 92141
  },
  {
    "billdate": "2018-09-01",
    "outlet": "KOLAR",

    "discount": 0,
    "GST": 5966,
    "amount": 115313
  },
  {
    "billdate": "2018-09-02",
    "outlet": "JAYANAGAR",

    "discount": 471,
    "GST": 28319,
    "amount": 511153
  },
  {
    "billdate": "2018-09-02",
    "outlet": "MALLESHWARAM",
           "discount": 0,
    "GST": 6198,
    "amount": 115704
  },
  {
    "billdate": "2018-09-02",
    "outlet": "KOLAR",

    "discount": 0,
    "GST": 4254,
    "amount": 83597
  },
  {
    "billdate": "2018-09-03",
    "outlet": "JAYANAGAR",

    "discount": 263,
    "GST": 9944,
    "amount": 167421
  },
  {
    "billdate": "2018-09-03",
    "outlet": "KOLAR",

    "discount": 0,
    "GST": 2693,
    "amount": 53775
  }
]

当在我的JSON中所有gross，Discount，Gst和Amount都存在时，将输出：

仅存在Discount，GST和Amount时，这将被输出：

对于其他人也是如此。

这四个gross，discount，GST和amount是动态用户正在选择一个，两个或全部，然后我要填充表格。

Answer 1

//added createTable function >> is called on body on load
function createTable(){
    let formatedData = formatData(data);
    renderTable(formatedData);
}   

var data = [{
    "billdate": "2018-09-01",
    "outlet": "JAYANAGAR",
    "gross": 451458,
    "discount": 513,
    "GST": 25357,
    "amount": 476426
  },
  {
    "billdate": "2018-09-01",
    "outlet": "MALLESHWARAM",
    "gross": 87190,
    "discount": 0,
    "GST": 4930,
    "amount": 92141
  },
  {
    "billdate": "2018-09-01",
    "outlet": "KOLAR",
    "gross": 109308,
    "discount": 0,
    "GST": 5966,
    "amount": 115313
  },
  {
    "billdate": "2018-09-02",
    "outlet": "JAYANAGAR",
    "gross": 483194,
    "discount": 471,
    "GST": 28319,
    "amount": 511153
  },
  {
    "billdate": "2018-09-02",
    "outlet": "MALLESHWARAM",
    "gross": 109483,
    "discount": 0,
    "GST": 6198,
    "amount": 115704
  },
  {
    "billdate": "2018-09-02",
    "outlet": "KOLAR",
    "gross": 79305,
    "discount": 0,
    "GST": 4254,
    "amount": 83597
  },
  {
    "billdate": "2018-09-03",
    "outlet": "JAYANAGAR",
    "gross": 157660,
    "discount": 263,
    "GST": 9944,
    "amount": 167421
  },
  {
    "billdate": "2018-09-03",
    "outlet": "KOLAR",
    "gross": 51059,
    "discount": 0,
    "GST": 2693,
    "amount": 53775
  }
]
let formatData = function(data) {
  let billdates = [];
  let outlets = [];
  let arr=[];

  data.forEach(element => {
    if (billdates.indexOf(element.billdate) == -1) {
      billdates.push(element.billdate);

    }
    if (outlets.indexOf(element.outlet) == -1) {
      outlets.push(element.outlet);
      outlets.push();
        //checking for property of each object of array "data" and if property exists adding to custom_Obj >> then adding to array and returning.
      var jsonObj= {};
      if(element.hasOwnProperty("gross")){
             jsonObj["gross"]=element.gross;
      }
      if(element.hasOwnProperty("discount")){
          jsonObj["discount"]=element.discount;
      }
      if(element.hasOwnProperty("GST")){
         jsonObj["GST"]=element.GST;
      }
      if(element.hasOwnProperty("amount")){
             jsonObj["amount"]=element.amount;
      }
      arr.push(jsonObj);

    }

  });
  return {
    data: data,
    billdates: billdates,
    outlets: outlets,
    arr:arr

  };
}


let renderTable = function(data) {
  var arr=data.arr;
  billdates = data.billdates;
  outlets = data.outlets;

  data = data.data;



  let tbl = document.getElementById("dailySales");
  let table = document.createElement("table");
  let thead = document.createElement("thead");
  let headerRow = document.createElement("tr");
  let th = document.createElement("th");
  th.innerHTML = "BillDate";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  let grandTotal = 0;
  let grandGross = 0;
  let grandDiscount = 0;
  let grandGst = 0;
  let outletWiseTotal = {};
  let outletWiseGross = {};
  let outletWiseDiscount = {};
  let outletWiseGst = {};
  th = document.createElement("th");
  th.colSpan = 4;
  th.innerHTML = "Total";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  outlets.forEach(element => {

    th = document.createElement("th");
    th.colSpan = 4;
    th.innerHTML = element;
    th.classList.add("text-center");
    headerRow.appendChild(th);

    outletWiseTotal[element] = 0;
    outletWiseGross[element] = 0;
    outletWiseDiscount[element] = 0;
    outletWiseGst[element] = 0;
    data.forEach(el => {
      if (el.outlet == element) {
        outletWiseTotal[element] += parseInt(el.amount);
        outletWiseGross[element] += parseInt(el.gross);
        outletWiseDiscount[element] += parseInt(el.discount);
        outletWiseGst[element] += parseInt(el.GST);
      }
    });
    grandTotal += outletWiseTotal[element]; //calculating totals for Total column
    grandGross += outletWiseGross[element];
    grandDiscount += outletWiseDiscount[element];
    grandGst += outletWiseGst[element];
  });

  thead.appendChild(headerRow);
  headerRow = document.createElement("tr");
  th = document.createElement("th");
  th.innerHTML = "";
  headerRow.appendChild(th);

 //As in this code you are creating "total" column  explicitly and not by json,So to create the header for the total column I am adding this headers to array[0] manually.
 //Otherwise header for that column cannot be populated dynamically.
 //Or you can add a dummy header obj in data array.
var totalcoloumn_obj={"gross":"","discount":"","GST":"","amount":""};
//as you showed total column in first, I am shifiting the array index by 1 and adding the total dymmy object at first index.
arr.unshift(totalcoloumn_obj);

//Creating column headers dynamically based on the data array that you declared on the top.


     for (var j = 0; j < arr.length; j++) {

         for(var key in arr[j]) {

             var th_dynamic = document.createElement("TH");
            var t = document.createTextNode(key);
            th_dynamic.appendChild(t);
            th_dynamic.classList.add("text-center");
             headerRow.appendChild(th_dynamic);

         }

        }




  headerRow.insertBefore(th, headerRow.children[1]);
  thead.appendChild(headerRow);
  table.appendChild(thead);

  headerRow = document.createElement("tr");
  td = document.createElement("th");
  td.innerHTML = "Total";
  td.classList.add("text-center");
  headerRow.appendChild(td);

  outlets.forEach(element => { // these are the table rows for each column
    td = document.createElement("th");
    td.innerHTML = outletWiseGross[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseDiscount[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseGst[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);

    td = document.createElement("th");
    td.innerHTML = outletWiseTotal[element].toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.appendChild(td);


  });
  td = document.createElement("th");
  td.innerHTML = grandTotal.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandGst.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandDiscount.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);

  td = document.createElement("th");
  td.innerHTML = grandGross.toLocaleString('en-IN');
  td.classList.add("text-right");
  headerRow.insertBefore(td, headerRow.children[1]);


  thead.appendChild(headerRow);
  table.appendChild(thead);

  let tbody = document.createElement("tbody");
  billdates.forEach(element => {
    let row = document.createElement("tr");
    td = document.createElement("td");
    td.innerHTML = element;
    row.appendChild(td);

    let total = 0;
    let totalGross = 0;
    let totalDiscount = 0;
    let totalGST = 0;
    outlets.forEach(outlet => {
      let ta = 0;
      let tg = 0;
      let tdi = 0;
      let tgst = 0;
      data.forEach(d => {
        if (d.billdate == element && d.outlet == outlet) {
          total += parseInt(d.amount);
          totalGross += parseInt(d.gross);
          totalDiscount += parseInt(d.discount);
          totalGST += parseInt(d.GST);
          ta = d.amount;
          tg = d.gross;
          tdi = d.discount;
          tgst = d.GST;
        }
      });

      td = document.createElement("td");
      td.innerHTML = tg.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = tdi.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = tgst.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);

      td = document.createElement("td");
      td.innerHTML = ta.toLocaleString('en-IN');
      td.classList.add("text-right");
      row.appendChild(td);




    });


    td = document.createElement("td");
    td.innerHTML = total.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);

    td = document.createElement("td");
    td.innerHTML = totalGST.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);

    td = document.createElement("td");
    td.innerHTML = totalDiscount.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);



    td = document.createElement("td");
    td.innerHTML = totalGross.toLocaleString('en-IN');
    td.classList.add("text-right");
    row.insertBefore(td, row.children[1]);


    tbody.appendChild(row);
  });

  table.appendChild(tbody);
  tbl.innerHTML = "";
  tbl.appendChild(table);
  table.classList.add("table");
  table.classList.add("table-striped");
  table.classList.add("table-bordered");
  table.classList.add("table-hover");
}

<!DOCTYPE html>
<html lang="en">
    <head>
    <meta charset="utf-8" />
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script type="text/javascript" src="Utility.js"></script>
  </head>
  <body onLoad="createTable();">
    <div align="left" class="table table-responsive" id="commonDvScroll">
      <table id="dailySales"></table>
    </div>
</body>

</html>

Answer 2

尝试这样，我已经从Anilm's答案中修改了一些代码。我希望这对您有用。

//added createTable function >> is called on body on load
function createTable(){
    let formatedData = formatData(data);
    renderTable(formatedData);
}   
var hasGross    = false;;
var hasGST      = false;
var hasDiscount = false;
var hasTotal = false;



var data = [{
    "billdate": "2018-09-01",
    "outlet": "JAYANAGAR",
    "discount": 513,
    "gross": 25357,
    "amount": 476426
  },
  {
    "billdate": "2018-09-01",
    "outlet": "MALLESHWARAM",
    "discount": 0,
    "gross": 4930,
    "amount": 92141
  },
  {
    "billdate": "2018-09-01",
    "outlet": "KOLAR",
    "discount": 0,
    "gross": 5966,
    "amount": 115313
  },
  {
    "billdate": "2018-09-02",
    "outlet": "JAYANAGAR",
    "discount": 471,
    "gross": 28319,
    "amount": 511153
  },
  {
    "billdate": "2018-09-02",
    "outlet": "MALLESHWARAM",
    "discount": 0,
    "gross": 6198,
    "amount": 115704
  },
  {
    "billdate": "2018-09-02",
    "outlet": "KOLAR",
    "discount": 0,
    "gross": 4254,
    "amount": 83597
  },
  {
    "billdate": "2018-09-03",
    "outlet": "JAYANAGAR",
    "discount": 263,
    "gross": 9944,
    "amount": 167421
  },
  {
    "billdate": "2018-09-03",
    "outlet": "KOLAR",
    "discount": 0,
    "gross": 2693,
    "amount": 53775
  }
]
let formatData = function(data) {
  let billdates = [];
  let outlets = [];
  let arr=[];

  data.forEach(element => {
    if (billdates.indexOf(element.billdate) == -1) {
      billdates.push(element.billdate);

    }
    if (outlets.indexOf(element.outlet) == -1) {
      outlets.push(element.outlet);
      outlets.push();
        //checking for property of each object of array "data" and if property exists adding to custom_Obj >> then adding to array and returning.
          var jsonObj= {};
      if(element.hasOwnProperty("gross")){
          hasGross = true;
             jsonObj["gross"]=element.gross;
     }
      if(element.hasOwnProperty("discount")){
          hasDiscount = true;
          jsonObj["discount"]=element.discount;
     }
     if(element.hasOwnProperty("GST")){
         hasGST = true;
         jsonObj["GST"]=element.GST;
     }
      if(element.hasOwnProperty("amount")){
          hasTotal = true;
             jsonObj["amount"]=element.amount;
     }


        arr.push(jsonObj);

    }

  });
  return {
    data: data,
    billdates: billdates,
    outlets: outlets,
    arr:arr

  };
}


let renderTable = function(data) {
    var arr=data.arr;
  billdates = data.billdates;
  outlets = data.outlets;

  data = data.data;



  let tbl = document.getElementById("dailySales");
  let table = document.createElement("table");
  let thead = document.createElement("thead");
  let headerRow = document.createElement("tr");
  let th = document.createElement("th");
  th.innerHTML = "BillDate";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  let grandTotal = 0;
  let grandGross = 0;
  let grandDiscount = 0;
  let grandGst = 0;
  let outletWiseTotal = {};
  let outletWiseGross = {};
  let outletWiseDiscount = {};
  let outletWiseGst = {};
  th = document.createElement("th");
  let cols = 0;
  if(hasGST){
    cols++;
  }
  if(hasGross){
    cols++
  }
  if(hasDiscount){
    cols++
  }
  if(hasTotal){
    cols++
  }
  th.colSpan = cols;
  th.innerHTML = "Total";
  th.classList.add("text-center");
  headerRow.appendChild(th);
  outlets.forEach(element => {

    th = document.createElement("th");
    th.colSpan = cols
    th.innerHTML = element;
    th.classList.add("text-center");
    headerRow.appendChild(th);

    outletWiseTotal[element] = 0;
    outletWiseGross[element] = 0;
    outletWiseDiscount[element] = 0;
    outletWiseGst[element] = 0;
    data.forEach(el => {
      if (el.outlet == element) {
        if(hasTotal){
            outletWiseTotal[element] += parseInt(el.amount);
        }
        if(hasGross){
          outletWiseGross[element] += parseInt(el.gross);
        }
        if(hasDiscount){
            outletWiseDiscount[element] += parseInt(el.discount);
        }
        if(hasGST){
            outletWiseGst[element] += parseInt(el.GST);
        }
      }
    });
    if(hasTotal){
        grandTotal += outletWiseTotal[element]; //calculating totals for Total column
    }
    if(hasGross){
      grandGross += outletWiseGross[element];
    }
    if(hasDiscount){
        grandDiscount += outletWiseDiscount[element];
    }
    if(hasGST){
        grandGst += outletWiseGst[element];
    }
  });

  thead.appendChild(headerRow);
  headerRow = document.createElement("tr");
  th = document.createElement("th");
  th.innerHTML = "";
  headerRow.appendChild(th);

 //As in this code you are creating "total" column  explicitly and not by json,So to create the header for the total column I am adding this headers to array[0] manually.
 //Otherwise header for that column cannot be populated dynamically.
 //Or you can add a dummy header obj in data array.
var totalcoloumn_obj={};
if(hasGross){
    totalcoloumn_obj.gross = "";
}
if(hasDiscount){
    totalcoloumn_obj.discount = "";
}
if(hasGST){
    totalcoloumn_obj.GST = "";
}
if(hasTotal){
    totalcoloumn_obj.amount = "";
}
//as you showed total column in first, I am shifiting the array index by 1 and adding the total dymmy object at first index.
arr.unshift(totalcoloumn_obj);

//Creating column headers dynamically based on the data array that you declared on the top.


     for (var j = 0; j < arr.length; j++) {

         for(var key in arr[j]) {

             var th_dynamic = document.createElement("TH");
            var t = document.createTextNode(key);
            th_dynamic.appendChild(t);
            th_dynamic.classList.add("text-center");
             headerRow.appendChild(th_dynamic);

         }

        }




  headerRow.insertBefore(th, headerRow.children[1]);
  thead.appendChild(headerRow);
  table.appendChild(thead);

  headerRow = document.createElement("tr");
  td = document.createElement("th");
  td.innerHTML = "Total";
  td.classList.add("text-center");
  headerRow.appendChild(td);

  outlets.forEach(element => { // these are the table rows for each column

    if(hasGross){
        td = document.createElement("th");
        td.innerHTML = outletWiseGross[element].toLocaleString('en-IN');
        td.classList.add("text-right");
        headerRow.appendChild(td);
    }

    if(hasDiscount){
        td = document.createElement("th");
        td.innerHTML = outletWiseDiscount[element].toLocaleString('en-IN');
        td.classList.add("text-right");
        headerRow.appendChild(td);
    }

    if(hasGST){
        td = document.createElement("th");
        td.innerHTML = outletWiseGst[element].toLocaleString('en-IN');
        td.classList.add("text-right");
        headerRow.appendChild(td);
    }

    if(hasTotal){
        td = document.createElement("th");
        td.innerHTML = outletWiseTotal[element].toLocaleString('en-IN');
        td.classList.add("text-right");
        headerRow.appendChild(td);
    }


  });
  if(hasTotal){
    td = document.createElement("th");
    td.innerHTML = grandTotal.toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.insertBefore(td, headerRow.children[1]);
  }

    if(hasGST){
        td = document.createElement("th");
        td.innerHTML = grandGst.toLocaleString('en-IN');
        td.classList.add("text-right");
        headerRow.insertBefore(td, headerRow.children[1]);
    }

  if(hasDiscount){
    td = document.createElement("th");
    td.innerHTML = grandDiscount.toLocaleString('en-IN');
    td.classList.add("text-right");
    headerRow.insertBefore(td, headerRow.children[1]);
  }

  if(hasGross)
  {
      td = document.createElement("th");
      td.innerHTML = grandGross.toLocaleString('en-IN');
      td.classList.add("text-right");
      headerRow.insertBefore(td, headerRow.children[1]);
    }


  thead.appendChild(headerRow);
  table.appendChild(thead);

  let tbody = document.createElement("tbody");
  billdates.forEach(element => {
    let row = document.createElement("tr");
    td = document.createElement("td");
    td.innerHTML = element;
    row.appendChild(td);

    let total = 0;
    let totalGross = 0;
    let totalDiscount = 0;
    let totalGST = 0;
    outlets.forEach(outlet => {
      let ta = 0;
      let tg = 0;
      let tdi = 0;
      let tgst = 0;
      data.forEach(d => {
        if (d.billdate == element && d.outlet == outlet) {
          if(hasTotal){
            total += parseInt(d.amount);
            ta = d.amount;
          }
          if(hasDiscount){
            totalDiscount += parseInt(d.discount);
            tdi = d.discount;
          }
          if(hasGST){
            totalGST += parseInt(d.GST);
            tgst = d.GST;
          }

          if(hasGross){
            totalGross += parseInt(d.gross);
            tg = d.gross;
          }


        }
      });
        //console.log(tg)
      if(hasGross){
          td = document.createElement("td");
          td.innerHTML = tg.toLocaleString('en-IN');
          td.classList.add("text-right");
          row.appendChild(td);
      }

      if(hasDiscount){
        td = document.createElement("td");
        td.innerHTML = tdi.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.appendChild(td);
      }

      if(hasGST){
        td = document.createElement("td");
        td.innerHTML = tgst.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.appendChild(td);
      }

      if(hasTotal){
        td = document.createElement("td");
        td.innerHTML = ta.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.appendChild(td);
      }




    });


    if(hasTotal){
        td = document.createElement("td");
        td.innerHTML = total.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.insertBefore(td, row.children[1]);
    }

    if(hasGST){
        td = document.createElement("td");
        td.innerHTML = totalGST.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.insertBefore(td, row.children[1]);
    }

    if(hasDiscount){
        td = document.createElement("td");
        td.innerHTML = totalDiscount.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.insertBefore(td, row.children[1]);
    }


    if(hasGross){
        td = document.createElement("td");
        td.innerHTML = totalGross.toLocaleString('en-IN');
        td.classList.add("text-right");
        row.insertBefore(td, row.children[1]);
    }


    tbody.appendChild(row);
  });

  table.appendChild(tbody);
  tbl.innerHTML = "";
  tbl.appendChild(table);
  table.classList.add("table");
  table.classList.add("table-striped");
  table.classList.add("table-bordered");
  table.classList.add("table-hover");
}

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script type="text/javascript" src="Utility.js"></script>
  </head>
  <body onLoad="createTable();">
    <div align="left" class="table table-responsive" id="commonDvScroll">
      <table id="dailySales"></table>
    </div>
  </body>

</html>

Answer 3

尝试：

thisSpan = 4;

th.setAttribute('colSpan', thisSpan );