What does the php class object refer to?

The object of the PHP class refers to the object created after the class is instantiated. It is also called an instance or an object. In object-oriented programming, a class is an abstract design that describes a collection of objects with the same properties and methods, while an object is an instantiation of a class and is a concrete entity.

In PHP, you can create an object by using the new keyword, and the process of creating an object is called instantiation. The way to create an object is as follows:

$classObj = new ClassName();  // 创建一个对象

Among them, $classObj represents the object of the class, and ClassName represents the name of the class. In memory, the program allocates space for the object and initializes the object according to the properties and methods defined in the class. At this point, the object can be manipulated by reference.

For example, in a Person class, we define two attributes: name and age, and a sayHi() method to say hello. We can create a Person object in the following way:

class Person {
  public $name;
  public $age;
  
  public function sayHi() {
    echo "Hi, my name is " . $this->name . " and I am " . $this->age . " years old.";
  }
}

$person = new Person();  // 创建Person对象
$person->name = "John";   // 设置$name属性
$person->age = 25;        // 设置$age属性
$person->sayHi();         // 调用sayHi()方法输出信息

In the above code, we create a Person object, set its name and age attributes, and finally call the sayHi() method to output the greeting information.

In short, the object of a PHP class refers to the specific entity created after the class is instantiated. It can access and operate the properties and methods of the class, and realize the features of encapsulation, inheritance and polymorphism in object-oriented programming.

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