JS reads the data from the EXCEL table, modifies the format and outputs it.

excel

this is my code

< html >

<head>
    <meta charset="UTF-8">
    <title></title>
    <script src="http://oss.sheetjs.com/js-xlsx/xlsx.full.min.js"></script>
    <script src="http://oss.sheetjs.com/js-xlsx/FileSaver.min.js"></script>
</head>

<body>
    <input type="file"onchange="importf(this)" />
    <div id="demo"></div>
    <script>
        
var to_json2 = function to_json(workbook) {
    var result = {};
    workbook.SheetNames.forEach(function(sheetName) {// workbook.SheetNames 
        var roa = XLSX.utils.sheet_to_json(workbook.Sheets[sheetName],{header:1});//json
        if(roa.length) result[sheetName] = roa;
    });
    console.log(JSON.stringify(result, 2, 2));
    return JSON.stringify(result, 2, 2);
};



function do_file(files) {
    rABS = true;
    var f = files[0];
    var reader = new FileReader();
    reader.onload = function(e) {
        if(typeof console !== "undefined") console.log("onload", new Date(), rABS);
        var data = e.target.result;
        if(!rABS) data = new Uint8Array(data);
        var wb=XLSX.read(data, {type: rABS ? "binary" : "array"});

        var json=to_json2(wb);
        
    };
    if(rABS) reader.readAsBinaryString(f);// html5
    else reader.readAsArrayBuffer(f);//ArrayBuffer html5
};
        
function importf(obj) {//
   if(!obj.files) {return;}
   do_file(obj.files);         
}

JS reads the data from the EXCEL table, modifies the format and outputs it.

problem description

the environmental background of the problems and what methods you have tried

related codes

what result do you expect? What is the error message actually seen?