The opposite of the constructor is the destructor. The destructor is a newly added content of php5. There is no destructor in php4. Destructors allow some operations or functions to be performed before a class is destroyed, which usually occurs automatically when all references to the class are reset or go out of scope. Similar to the name of the constructor, the name of a class's destructor must be __destruct(). The destructor cannot take any parameters.
If you declare a function in a class named __construct, this function will be treated as a constructor and executed when creating an object instance. To be clear, __ is two underscores. Just like any other function, a constructor may have parameters or default values. You can define a class to create an object and put all its properties in a statement. You can also define a function called __destruct, which PHP will call before the object is destroyed. It's called php destructor. Inheritance is a powerful feature of classes. One class (subclass/derived class) can inherit the functionality of another class (parent class/base class). The derived class will contain all the properties and methods of the base class, and can add other properties and methods in the derived class. You can also override base class methods and properties. As shown in 3.1.2, you can extend a class using the extends keyword. You may be wondering how constructors are inherited. When they are inherited along with other methods, they are not executed when the object is created. If you need this functionality, you need to use the :: operator. It allows you to point to a namespace. parent points to the parent class namespace. You can use parent::__construct to call the parent class's constructor. Some object-oriented languages name the constructor after the class. The same was true for previous versions of PHP, and this method is still valid. That is: if you name a class animal and create a method named animal in it, then this method is the constructor. If a class has both a __construt constructor and a function with the same name as the class, PHP will treat __construct as a constructor. This allows classes written in previous PHP versions to still be used. But new scripts (php5) should use __construct. This new way of declaring a constructor in PHP allows the constructor to have a unique name, regardless of the name of the class it is in. This way you don't need to change the name of the constructor when you change the name of the class. You may give the constructor in PHP an access method like other class methods. Access methods will affect the ability to instantiate objects from a certain range. This allows the implementation of some fixed design patterns, such as the singleton pattern. php destructor, the opposite of constructor. PHP calls them to destroy an object from memory. By default, PHP only releases the memory occupied by object properties and destroys object-related resources. Destructors allow you to execute arbitrary code to clear memory after using an object. When PHP decides that your script is no longer associated with the object, the PHP destructor will be called. Within a function's namespace, this occurs when the function returns. For global variables, this happens at the end of the script. If you want to explicitly destroy an object, you can assign any other value to the variable pointing to the object. Usually the variable is assigned to null or unset is called. The following example counts the number of objects instantiated from a class. The counter class starts to increase in value from the constructor and decreases in value in the PHP destructor. Once you define a class, you can use new to create an instance of this class. The class definition is the design drawing, and the instances are the components placed on the assembly line. new takes the name of a class and returns an instance of that class. If the constructor requires parameters, you should enter the parameters after new. example:
Program running results: 1 2 1 When a new PHP destructor instance is created, memory will be prepared to store all properties. Each instance has its own unique set of properties. But methods are shared by all instances of the class. |

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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