Uncaught TypeError: Cannot read property 'length' of undefined [code pen] issue

Question

User81789783 posted

i run my code in code pen [ https://codepen.io/someatoms/pen/adojWy?editors=1010] ,any one can run below both files in code pen and test

i m facing above mentioned error i.e

Uncaught TypeError: Cannot read property 'length' of undefined

i have below html file and js file ,but its giving an error

here is html file

<button onclick="generate()">Generate PDF</button>

<table id="basic-table" style="display: block;">
    <thead>

                <tr style="padding:0rem;">

                    <th style="width:4rem;padding:0rem!important;text-align: center;color: darkmagenta;max-width:4rem;">Frequency</th>
                    <th style="max-width:8rem;width:8rem;padding:0rem!important;text-align: center;color: darkmagenta;">Task Name</th>

                    <th style="width: 2rem;max-width:2rem;padding:0rem!important;text-align: center;color: darkmagenta;">Shift</th>
                        <th style="width: 3rem;max-width:3rem;padding:0rem!important;text-align: center;color: darkmagenta;">Range</th>

                
				
                </tr>
            </thead>



            <tbody>
                <tr>
                    <td colspan="35" style="padding:0">
                        <table class="table table-bordered">
                            <tr>

                                <td class="blank"  style="width:4rem;padding:0rem!important;text-align: center;border:0px;color: black;max-width:4rem;">
                                   
                                   dsadsa


                                </td>
                                <td  class="blank" style="max-width:8rem;border-bottom:0px;width:8rem;padding:0rem!important;text-align: center;color: black;">

                                   sadads


                                </td>
                                <td style="width:2rem;max-width:2rem;border:1px">

                                    IST


                                </td>

                                <td  class="blank" style="width:3rem;max-width:3rem;">

                                    asdasd


                                </td>
                               
                              
                            </tr>

                          
                           
                            


                        </table>

                    </td>
                </tr>




            </tbody>
</table>

and here is js file

function generate() {

  var doc = new jsPDF('l', 'pt');

  var res = doc.autoTableHtmlToJson(document.getElementById("basic-table"));
  doc.autoTable(res.columns, res.data, {margin: {top: 80}});

  var header = function(data) {
    doc.setFontSize(8);
    doc.setTextColor(40);
    doc.setFontStyle('normal');
    //doc.addImage(headerImgData, 'JPEG', data.settings.margin.left, 20, 50, 50);
    doc.text("Testing Report", data.settings.margin.left, 50);
  };

  var options = {
    addPageContent  : header,
    columnStyles: {

                 0: { columnWidth: 15 }, 
                    1: { columnWidth: 22}, 
                    2: { columnWidth: 8.5 }, 
                    3: { columnWidth: 10.5}, 
                   
                 
                    
    },
    margin: {
        top: 10,
                    bottom: 40,
                    left: 1,
                    right: 1,
    },
    startY: doc.autoTableEndPosY() + 20,
      styles: {overflow: 'linebreak'},
    
     
        tableWidth: 'auto',
  };

  doc.autoTable(res.columns, res.data, options);

  doc.save("table.pdf");
}