Utilizing the Use Keyword for Namespaces in PHP 5 - Introducing the use keyword (
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For those programmers who suffer from chronic laziness and want to use a short syntax, PHP 5 provides yet another keyword, called "use," which can be utilized to link one or more classes to a particular namespace.
In order to illustrate more clearly the utilization of this handy keyword, below I included another code sample. It shows how to tie the same "User" class that you saw in the previous section to a fictional "UserManager::Blog" namespace.
Here's how this example in question looks:
// example on using the 'use' keyword
use UserManager::Blog::User;
class User{
private $firstName;
private $lastName;
private $email;
public function __construct($firstName,$lastName,$email){
if(!$firstName||strlen($firstName)>32){
throw new Exception('Invalid First Name parameter!');
}
if(!$lastName||strlen($lastName)>32){
throw new Exception('Invalid Last Name parameter!');
}
if(!$email||!preg_match("/^.+@.+..+$/",$email)){
throw new Exception('Invalid Email parameter!');
}
$this->firstName=$firstName;
$this->lastName=$lastName;
$this->email=$email;
}
// get user's first name
public function getFirstName(){
return $this->firstName;
}
// get user's last name
public function getLastName(){
return $this->lastName;
}
// get user's email
public function getEmail(){
return $this->email;
}
}
As shown in the above hands-on example, the "use" keyword comes in handy for shortening the syntax required for declaring a namespace. In this case, a hypothetical "User::Manager" namespace has been linked to the sample "User" class that you learned before, but naturally this reserved word can be used with other classes.
Hopefully, the example that you just saw has been educational enough to demonstrate how to employ the "use" keyword in a useful manner when it comes to associating a concrete class to a particular namespace. However, I must admit that the example in question is still incomplete, since I haven't shown you how to call an instance of a class that's been linked to a namespace via the aforementioned keyword.
Therefore, the last section of this tutorial will be focused exclusively on explaining this process in depth. But, do you know how to get there? Click on the link shown below and keep reading!
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