How to convert class into object in php

With the continuous development of computer programming, there are more and more programming languages, among which PHP language is one of the more popular languages. In the PHP language, the concepts of classes and objects are very important. A class is a collection of objects with the same properties and methods, and an object is an instance of a class. In PHP language, related operations are performed by converting classes into objects.

In the PHP language, the definition of a class is achieved through the class keyword. The format of declaring a class is: class class name {attributes and methods}, where attributes and methods are members of the class, and attribute definitions Methods define the state of a class, and methods define the behavior provided by the class.

In the PHP language, the defined class is actually a template. When using it, you need to instantiate it to generate an object. There are many ways to create instance objects through classes. Generally, there are three ways to create objects, namely new, clone, reflection.

The first method: new keyword, this method is the most commonly used way to create an object instance. Using the new keyword in the PHP language to initialize an object means creating an instance object of this type.

For example, we define a Student class:

class Student{
    public $name;
    public $age;
    public function sayHello(){
        echo "Hello, I am " . $this->name . ".";
    }
}

Use the new keyword to create an instance of the Student object:

$stu = new Student();
$stu->name = "Tom";
$stu->age = 18;
$stu->sayHello();

In the above code, we create it through the new keyword An instance object of the Student class is obtained, then the properties of the instance object are initialized, and finally the sayHello method is called to output the result.

The second method: clone keyword, this method is a way to create object instances added after PHP5. Through the clone keyword, you can create a copy of the original object and return it.

$stu1 = new Student();
$stu1->name = "Mike";
$stu1->age = 22;

$stu2 = clone $stu1;
$stu2->name = "Jordan";

echo $stu1->name; //输出Mike
echo $stu2->name; //输出Jordan

In the above code, we create a copy of $stu1 through the clone keyword, change the attribute value $name of the copy, and the final output results are Mike and Jordan. It should be noted that the attribute value $name of $stu1 has not changed.

The third way: reflection mechanism, through which you can access and operate the properties and methods of objects, such as getting class names, getting properties, calling methods, etc.

$stu = new Student();
$stu->name = "Jerry";
$stu->age = 20;

//获取类名
$class_name = get_class($stu);
echo $class_name . "\n"; //输出Student

//获取对象属性
$reflector = new ReflectionClass("Student");
$property = $reflector->getProperty("name");
echo $property->getValue($stu); //输出Jerry

//反射机制调用方法
$method = $reflector->getMethod("sayHello");
$method->invokeArgs($stu, array()); //输出Hello, I am Jerry.

In the above code, we obtained the $stu object through the reflection mechanism, thereby obtaining the class name, object attributes, and calling methods in the object.

Summary: Converting classes into objects is a very common operation in the PHP language. It can usually be implemented through new, clone, reflection mechanisms, etc. However, different methods are suitable for different scenarios. In practical applications, it is necessary to choose a suitable method to create and operate objects according to the specific situation, so as to realize the relevant functions of the program conveniently and quickly.

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