const greeting = _name => `hello ${_name}`;
      
     module.exports.greeting = greeting;demo05.js
    const a = require('./demo04.js');
     console.log(a);
     console.log(a.greeting(`geyao`));

const greeting = _name => `hello ${_name}`;
     const x = 100;
     exports.x = x;
     module.exports.greeting = greeting;
     module.exports = {
         name: 'zhangsan'
     }demo05.js
    const a = require('./demo04.js');
     console.log(a);
     //console.log(a.greeting(`geyao`));