text: const fs = require('fs');
  
  fs.writeFile('./b.txt', 'hello world', 'utf8', (err) => {
      if (err) throw err
      console.log('文件写入成功');
  })
  
  fs.writeFileSync('./c.txt', 'hello world', 'utf8');
  console.log("C写入成功");
  