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How to understand the inheritance of PHP class, in view of this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

The inheritance of PHP class is an important knowledge point in the learning of PHP language. So how do we correctly learn the inheritance of PHP classes? In PHP object-oriented programming, class inheritance is always the most critical.

This is like human beings having children (why do we have to have children? is it to prevent old age? I don't know), you take out some of your genes and some of your wife's genes and regenerate into a new individual, and this new personality will certainly contain the characteristics of both of you. This is a biological explanation of inheritance. In the world of programming, this inheritance is inheritance!

First of all, after understanding some of the living principles of inheritance, I want to see if the inheritance of the PHP class is no longer so mysterious. Maybe it is not mysterious in the first place, because we are too complicated. To have inheritance, there must be a "root", which you may imagine that you will give birth to a son or daughter, and they will get some "things (attributes and methods)" from you, so that your "offspring" will hold all your characteristics. Let's use syntax to describe how this is expressed in the object-oriented of PHP (it can't be as direct as humans, get married, and your offspring will be born after a while)

1. Generate a "root" class (parent or base class)

Syntax: class father {

}

1. Produce "descendants" (subclasses)

Syntax: class son extends father {

}

Description: the parent class is just an ordinary class. To have descendants, you only need to add an extends keyword to the normal class to OK, so that your subclass only has all the properties and methods of the parent class. It's as simple as that.

Let's do something practical. After all, defining a parent class and a child class in the inheritance of the PHP class is going to accomplish something. Here this task is relatively monotonous, take people, for example, people have names (attributes), people want to sleep and eat (methods). Let's use this basic task to complete the knowledge of this section.

< ?php class father{ protected $name; function __construct($name){ $this->

Name=$name;} function _ _ destruct () {echo "

< p>

{$this- > name} is also dying.

< br/>

< /p>

";} / / this is the so-called constructor that initializes function go_to_sleeping () {echo"

< p>

{$this- > name} wants to sleep.

< /p>

";} function eat () {echo"

< p>

{$this- > name} want to eat.

< /p>

";} class son extends father {function playing () {/ / the child can be very naughty. Of course, he also wants to eat the echo of the creature that wants to sleep."

< p>

{$this- > name} is making trouble.

< /p>

";} $your_father=new father (" dad "); $your_father- > go_to_sleeping (); $your_father- > eat (); $my_son=new son ('baby'); $my_son- > go_to_sleeping (); $my_son- > eat (); $my_son- > playing ();? >

< ?php class father{ protected $name; function __construct($name){ $this->

Name=$name;} function _ _ destruct () {echo "

< p>

{$this- > name} is also dying.

< br/>

< /p>

";} / / this is the so-called constructor that initializes function go_to_sleeping () {echo"

< p>

{$this- > name} wants to sleep.

< /p>

";} function eat () {echo"

{$this- > name} want to eat.

";} class son extends father {function playing () {/ / the child can be very naughty. Of course, he also wants to eat the echo of the creature that wants to sleep."

< p>

{$this- > name} is making trouble.

< /p>

";} $your_father=new father (" dad "); $your_father- > go_to_sleeping (); $your_father- > eat (); $my_son=new son ('baby'); $my_son- > go_to_sleeping (); $my_son- > eat (); $my_son- > playing ();? >

Parsing: in our example of using inheritance, we use the keywords mentioned in the constructor of PHP and the encapsulation of the PHP class. If there is anything you don't understand, take a look! I don't want to say any more. I don't want to sleep at noon. Tell me about this Mini Program.

In the father of the class, we define the general characteristics, such as the person's name, people have to eat and sleep, and then in its subclass (descendants) we define a personalized method (playing). After all, there are differences between people. We use the constructor to initialize the name, and of course we use the destructor to "destroy" the object, but you may not find that there are no constructors and destructors in the subclass, so the subclass inherits all the methods of the parent, otherwise how can you $my_son- > go_to_sleeping (); this is the inheritance of the PHP class.

This is the answer to the question on how to understand the inheritance of the PHP class. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel to learn more about it.

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