Node.js uses the fs module to write files

Use the fs. writeFile() method to write content to the specified file. The syntax format is as follows:

fs.writeFile(file,data[,options],callback)

Parameter interpretation:

File: string specifying a file path, representing the file storage path, a required parameter

Data: content to be written, required parameter

Options: What format to write the file in? Optional parameter. The default value is utf8

Callback: the callback function after the file is written, a required parameter

// 1.导入fs文件系统模块
const fs=require('fs')
// 2.调用fs.writeFile()方法，写入文件内容
//  参数一:指定一个文件路径的字符串，表示文件的存放路径，必选参数
//  参数二:要写入的内容，必选参数
//  参数三:文件写入完成后的回调函数，必选参数
fs.writeFile('./file.txt','hello Node.js',function(err,datastr){
    console.log(err)
})