mysqli_connect（）中的第四个参数是什么？

What is "forks" in mySQL

<?php  
$connect = mysqli_connect("db location","username","password", "forks") or die(mysql_error());
?>

Its database name

mysqli_connect(host,username,password,dbname,port,socket);

Parameter      Description
host           Optional. Specifies a host name or an IP address
username       Optional. Specifies the MySQL username
password       Optional. Specifies the MySQL password
dbname         Optional. Specifies the default database to be used
port           Optional. Specifies the port number to attempt to connect to the MySQL server
socket         Optional. Specifies the socket or named pipe to be used

Source: http://php.net/manual/en/function.mysqli-connect.php

In your example, forks is the fourth parameter, so it is simply the name of the database. The word forks is otherwise meaningless in MySQL, and doesn't bear any relevance to the code itself.

The parameters of the mysqli_connect() PHP function are as follows:

1. Host
2. Username
3. Password
4. Database Name
5. Port
6. Socket

See the PHP Manual for the mysqli::__construct() function, of which mysqli_connect is an alias.