How to introduce external values into class?
Question 1: does class receive external values?
class connection {
var $host = 'XXXX';
var $username = 'aaab';
var $password = 'aaa';
$do = new mysqli($host, $username, $password, $config['db']);
}I have changed the value of $config ['db '] according to the host on the top, so when I read database a when testing the domain and database B when I read the formal domain, but I find that I can't throw this in, and it will display an error. Like a general function, you can use global to receive external values, just add global $config; but how can I achieve this in class?
Question 2: does the function in class have to be global to receive external values? (although general functions also need to go through global, I would like to say that with the principle of object orientation, is it unnecessary?)
class get {
public function get_information() {
global $request;
$render = mysqli_fetch_array($do->query(
"SELECT * FROM `user`
WHERE `session` = '{$request['session']}' "
));
return $render;
}
}（ $ Do doesn't care about it, because problem one is still being solved. If it can be solved, you can use inheritance) when you use get of get class_ information () Announce global in it $ request ; To receive external values $ What is the way to request without using global? Can it be inherited? Or other ways. Thank you!
PHP class through the construction method__ Construct to pass parameters.
for instance:
<?php
class mydb {
protected $use_dbname;
protected $dbh;
public function __construct( $host, $username, $password, $dbname ) {
$this->dbh = new mysqli( $host, $username, $password, $dbname );
// 将传入的参数赋值到内部变量就可以在内部其他地方调用了
$this->use_dbname = $dbname;
}
public function query( $query ) {
// 这里可以获取 $this->use_dbname
$result = $this->dbh->query( $query );
return $result;
}
// more
}
// 使用
$mydb = new mydb( 'host', 'user', 'pwd', 'dbname' );
// $mydb->query('SELECT * FROM `user` WHERE user_id = 1;')
https://www.51-n.com/t-4004-1... You can take a look at this. I don't know if it can solve your problem
