I am looking a PHP script example that contains the mysqli extension. The code in question is as follows:
$conn = new mysqli("myServer", "myUser", "myPassword", "Northwind");
I'm confused as to wether this is a function or a class instance. If it is a function, is it possible to instantiate a function?
What confuses you is the constructor.
This is a special public function inside a class which get's called straight after an instance gets created.
mysqli
in your case is a class, which has a constructor like this:
public function __construct($server, $user, $password, $dbname) {
// do something
}
See:
http://php.net/manual/en/mysqli.construct.php
http://php.net/manual/en/language.oop5.decon.php
Geekfact:
You can somehow get an "instance" of a function by using closures. These arent real instances, just callables
.
function createInstance() {
return function($a, $b) {
return $a + $b;
};
}
$myIndependendFunction = createInstance();
echo $myIndependendFunction(3, 2); // prints 5
You declare functions and use it , you declare objects (mysqli object in this case) and you instantiate it .
You can read the manual. http://www.php.net/manual/en/language.oop5.basic.php
If you want to contain your instantiation logic in one place you could wrap your current code within a function and return the ready to use mysqli class?
Example:
<?php
function getMysqliConnection(){
return new mysqli("myServer", "myUser", "myPassword", "Northwind");
}
$conn = getMysqliConnection();
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