学习是最好的投资！
Solved changed to call format_phone(phone_number);
call format_phone(phone_number);
Reasons for different syntax
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Solved changed to
call format_phone(phone_number);Reasons for different syntax