Detailed explanation of using traits in PHP

　Traits in PHP 5.4 is a newly introduced feature. I really don’t know how to translate it accurately in Chinese. Its actual purpose is to use multiple inheritance in some situations, but PHP does not have multiple inheritance, so such a thing was invented.

Traits can be understood as a set of methods that can be called by different classes, but Traits are not classes! Cannot be instantiated. Let’s take an example to look at the syntax first:

<?php
trait myTrait{
    function traitMethod1(){}
    function traitMethod2(){}
}
//然后是调用这个traits,语法为：
class myClass{
    use myTrait;
}
//这样就可以通过use myTraits，调用Traits中的方法了，比如：
$obj = new myClass();
$obj-> traitMethod1 ();
$obj-> traitMethod2 ();

Next, let’s explore why we use traits. For example, there are two classes, business and Individual, both of which have address attributes. , the traditional approach is to abstract a parent class that both classes have common characteristics, such as client, and set the access attributes address, business and individual in the client class to inherit them respectively, as follows:

// Class Client  
class Client  {  
    private $address;  
    public getAddress() {  
        return $this->address;  
    }       
    public setAddress($address) {  
        $this->address = $address;    
    }  
}  
class Business extends Client{  
    //这里可以使用address属性  
}  
// Class Individual  
class Individual extends Client{  
//这里可以使用address属性  
}

But if There is a class called order that needs to access the same address attribute, so what should I do? The order class cannot inherit the client class because this does not comply with the principles of OOP. Traits come in handy at this time. You can define a trait to define these public properties.

// Trait Address
trait Address{
    private $address;
    public getAddress() {
        eturn $this->address;
    }
    public setAddress($address) {
        $this->address = $address;
    }
}
// Class Business
class Business{
    use Address;
    // 这里可以使用address属性
}
// Class Individual
class Individual{
    use Address;
    //这里可以使用address属性
}
// Class Order
class Order{
    use Address;
    //这里可以使用address属性
}