how to change the default port of mysql on CentOS 7

how to change the default 3306 port of mysql on CentOS 7, it's very simple.
step1:You need to edit your my.cnf(vim /etc/my.cnf), add or modify the line. 

1. port=3306 

change the default port of mysql from 3306 to 3388, as follows.

1. [mysqld]
2. datadir=/var/lib/mysql
3. socket=/var/lib/mysql/mysql.sock
4. user=mysql
5. # Disabling symbolic-links is recommended to prevent assorted security risks
6. symbolic-links=0
7. port=3388
8. [mysqld_safe]
9. log-error=/var/log/mysqld.log
10. pid-file=/var/run/mysqld/mysqld.pid

step2:Restart mysql server on CentOS 7.

1. # systemctl restart mysqld

step3:Check what port mysql is running on. run netstat -ntlp command.

1. [root@VM_230_32_centos ~]# netstat -ntlp
2. Active Internet connections (only servers)
3. Proto Recv-Q Send-Q Local Address         Foreign Address       State       PID/Program name   
4. tcp        0      0 0.0.0.0:3388          0.0.0.0:*             LISTEN      6944/mysqld         
5. tcp        0      0 0.0.0.0:80            0.0.0.0:*             LISTEN      6998/httpd          
6. tcp        0      0 0.0.0.0:4369          0.0.0.0:*             LISTEN      30342/epmd          
7. tcp        0      0 0.0.0.0:22            0.0.0.0:*             LISTEN      1062/sshd           
8. tcp        0      0 127.0.0.1:25          0.0.0.0:*             LISTEN      1154/master

thanks!