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This article mainly introduces "how to judge whether an object belongs to a class in PHP". In daily operation, I believe that many people have doubts about how to judge whether an object belongs to a class in PHP. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the doubt of "how to judge whether an object belongs to a class in PHP". Next, please follow the editor to study!

In PHP, if you want to judge whether an object belongs to a class, you need to use instanceof. You can use the instanceof keyword to determine whether an object is an instance of a class, a subclass of a class, or implements a specific interface, and perform corresponding operations. This can be used to determine whether an object belongs to a certain category, and its syntax format is as follows:

Object name instanceof class name

Determine whether an object belongs to a class or not

To determine whether an object belongs to a class, through the instanceof keyword, in syntax format, if the object belongs to this class, it returns true;. If it does not belong to this class, it returns flase.

Next, let's use an example to see whether an object belongs to a class. Examples are as follows:

Output result:

As can be seen from the above results, the detected object belongs to the study class, and the returned result is true, while the detected object does not belong to the study1 class, so flase is returned. Therefore, it is possible to judge whether an object belongs to a class or not through instanceof.

Determine whether an object belongs to a subclass of a parent class

Through the above case, we have been able to judge whether an object belongs to a class, not only that, but also through instanceof to determine whether an object is inherited from a subclass of a parent class. Similarly, if the detected object belongs to a subclass of this parent class, the return result is true, and if the detected object does not belong to a subclass of this parent class, the return result is flase.

Next, let's take a look at the example, which is as follows:

Output result:

As can be seen from the above results, it is also possible to determine whether an object inherits from a subclass of a parent class through instanceof.

Determine whether an object belongs to an interface object

We can also use instanceof to determine whether a variable is an object that implements an interface. Similarly, if the output result is true, it means that the object belongs to this interface. If the output result is flase, it means that the object does not belong to this interface.

Let's take a look at the example, which is as follows:

Output result:

In the above example, instanceof is used to determine whether a variable is an object of an interface.

When the object of judgment does not exist

We also need to note that if the detected variable is not an object, will there be any change in the returned result and whether it will have any impact? Instanceof does not report an error but returns flase directly.

Let's take a look at the example, which is as follows:

Output result:

As can be seen from the above example, the variable being monitored is not an object, and the system does not report an error, but returns flase.

At this point, the study on "how to judge whether an object belongs to a class in PHP" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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