PHP Magic Law __set and __get

Set andGet is a common 2 magic method in object-oriented.
? set: When assigning a value to an inaccessible property,Set () is called. The syntax is as follows:

public void __set ( string $name , mixed $value )

? Get: Gets () is called when the value of an inaccessible property is read. The syntax is as follows:

public mixed __get ( string $name )

Description: The parameter $name refers to the name of the variable to be manipulated. The $value parameter of the __set () method specifies the value of the $name variable.
The sample code is as follows:

<?phpclass sportobject{//class sportobjectprivate $type = '; Private variable $typepublic function __get ($name) {//Declares Magic Method __get () echo "Tune        Use the __get method \ n "; if (Isset ($this-$name)) {//Determine if the variable is declared echo ' variable '. $name. ' The value is: '. $this-$name. '        <br> '; }else{echo ' variable '. $name. '             Undefined, initialized to 0<br> ';                             $this-$name = 0; If not declared, initialize the variable}} public function __set ($name, $value) {//Declare Magic Method __set () echo        "Call __set method \ n";            if (Isset ($this, $name)) {//Determine if the variable is defined $this, $name = $value; echo ' variable '. $name. ' The assignment is: '. $value. '        <br> ';                            }else{$this $name = $value; If undefined, the variable is continued to be assigned the echo ' variable '. $name. ' was initialized to: '. $value. '     <br> '; Output warningMessage}} public function test () {echo $this->type;                                }} $MyComputer = new Sportobject ();                                    Instantiated Object $mycomputer$mycomputer-type = ' DIY ';                                        Assign a value $MyComputer-type to a variable;                                        Call variable $type$mycomputer CPU; Call Variable $name?>

Code parsing:

1. Call $MyComputer-type = ' DIY '; Assigning a value to the Type property, because the Type property is private and cannot be accessed outside the class, calls the set () Magic method, first judging the isset ($this-$name) in the IF statement, according to set ($name, $ Value), we know that the value of $name is type, the value of $value is Diy,isset ($this, $name) is Isset ($this->type), the previous reference to type this property is private, But inside the class is callable, so if statement is set up, execute the following code:

$this $name = $value;
echo ' variable '. $name. ' The assignment is: '. $value. ' <br> ';

2.  调用$MyComputer->type, 是读取type属性，同理，执行__get($name)方法。首先判断isset($this->$name)，if语句成立，执行下面代码：

echo ' variable '. $name. ' The value is: '. $this-$name. ' <br> ';
Since the previous assignment for $this->type is DIY, it is output directly.

3.  调用$MyComputer -> cpu; 读取cpu这个不存在属性，调用__get($name)方法，首先判断if语句isset($this->$name),由于没有这个cup属性，所以执行else语句内容，代码如下：

echo ' variable '. $name. ' Undefined, initialized to 0<br> ';
$this-$name = 0;

在代码最后，调用了$this->$name = 0; 即为不存在的属性赋值，所以会再次调用__set($name)方法。同样是判断if语句，这时if语句为false,执行else中的代码如下：

$this $name = $value;
echo ' variable '. $name. ' was initialized to: '. $value. ' <br> ';

PHP Magic Law __set and __get