js实现下载.txt文件，当后端没有提供接口的时候

1.采用a标签的download属性实现下载

/*
* fileName: txt文件名称
* content：文件内容(string)
*/
function downloadTxt(fileName, content) {
    let element = document.createElement('element');
    element.href = 'data:text/plain;charset=utf-8,' + content
    element.download = fileName
    document.body.appendChild(element);
    element.click();
    document.body.removeChild(element);
}

2.通过文件流的形式下载（通过FileReader转化为base64字符串下载）

function downloadTxt(fileName, content) {
   let blob = new Blob([content], {
       type: "text/plain;charset=utf-8"
    });
   let reader = new FileReader();
   reader.readAsDataURL(blob);
   reader.onload = function(e) {
	  let element = document.createElement('element');
	  element.download = fileName;
	  element.href = e.target.result;
	  document.body.appendChild(element);
	  element.click();
	  document.body.removeChild(element);
  }
}