话不多说，直接贴代码，当然代码我是百度搜来的，我只是代码的搬运工
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="http://oss.sheetjs.com/js-xlsx/xlsx.full.min.js"></script>
<script src="FileSaver.js"></script>
</head>
<body>
<input type="file"onchange="importf(this)" />
<button onclick="downloadExl(sbData)">导出</button>
<div id="demo"></div>
<script>
/*
FileReader共有4种读取方法：
1.readAsArrayBuffer(file)：将文件读取为ArrayBuffer。
2.readAsBinaryString(file)：将文件读取为二进制字符串
3.readAsDataURL(file)：将文件读取为Data URL
4.readAsText(file, [encoding])：将文件读取为文本，encoding缺省值为'UTF-8'
*/
var wb;//读取完成的数据
var rABS = false; //是否将文件读取为二进制字符串
var sbData;
function importf(obj) {//导入
if(!obj.files) {
return;
}
var f = obj.files[0];
var reader = new FileReader();
reader.onload = function(e) {
var data = e.target.result;
if(rABS) {
wb = XLSX.read(btoa(fixdata(data)), {//手动转化
type: 'base64'
});
} else {
wb = XLSX.read(data, {
type: 'binary'
});
}
//wb.SheetNames[0]是获取Sheets中第一个Sheet的名字
//wb.Sheets[Sheet名]获取第一个Sheet的数据
document.getElementById("demo").innerHTML= JSON.stringify( XLSX.utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]) );
sbData=XLSX.utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
for(var i=0,l=sbData.length;i<l;i++){
//循环处理数据过程
}
};
if(rABS) {
reader.readAsArrayBuffer(f);
} else {
reader.readAsBinaryString(f);
}
}
function fixdata(data) { //文件流转BinaryString
var o = "",
l = 0,
w = 1024;
for(; l < data.byteLength / w; ++l) o += String.fromCharCode.apply(null, new Uint8Array(data.slice(l * w, l * w + w)));
o += String.fromCharCode.apply(null, new Uint8Array(data.slice(l * w)));
return o;
}
function downloadExl(data, type) {
var keys = Object.keys(data[0]);
var firstRow = {};
keys.forEach(function (item) {
firstRow[item] = item;
});
data.unshift(firstRow);
var content = {};
// 把json格式的数据转为excel的行列形式
var sheetsData = data.map(function (item, rowIndex) {
return keys.map(function (key, columnIndex) {
return Object.assign({}, {
value: item[key],
position: (columnIndex > 25 ? getCharCol(columnIndex) : String.fromCharCode(65 + columnIndex)) + (rowIndex + 1),
});
});
}).reduce(function (prev, next) {
return prev.concat(next);
});
sheetsData.forEach(function (item, index) {
content[item.position] = { v: item.value };
});
//设置区域,比如表格从A1到D10,SheetNames:标题，
var coordinate = Object.keys(content);
var workBook = {
SheetNames: ["helloSheet"],
Sheets: {
"helloSheet": Object.assign({}, content, { "!ref": coordinate[0] + ":" + coordinate[coordinate.length - 1] }),
}
};
//这里的数据是用来定义导出的格式类型
var excelData = XLSX.write(workBook, { bookType: "xlsx", bookSST: false, type: "binary" });
var blob = new Blob([string2ArrayBuffer(excelData)], { type: "" });
saveAs(blob, "hello.xlsx");
}
//字符串转字符流
function string2ArrayBuffer(s) {
var buf = new ArrayBuffer(s.length);
var view = new Uint8Array(buf);
for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
return buf;
}
// 将指定的自然数转换为26进制表示。映射关系：[0-25] -> [A-Z]。
function getCharCol(n) {
let temCol = "",
s = "",
m = 0
while (n > 0) {
m = n % 26 + 1
s = String.fromCharCode(m + 64) + s
n = (n - m) / 26
}
return s
}