Examples of __set and __get usage in PHP

class Person {
    function __get( $property ) {
        $method = "get{$property}";
        if ( method_exists( $this, $method ) ) {
            return $this->$method();
        }
    }
    function __isset( $property ) {
        $method = "get{$property}";
        return ( method_exists( $this, $method ) );
    }
    function getName() {
        return "Bob";
    }

    function getAge() {
        return 44;
    }
}
print "";</li>
<li>$p = new Person();</li>
<li>if ( isset( $p->name ) ) {</li>
<li>    print $p->name;</li>
<li>} else {</li>
<li>    print "nopen";</li>
<li>}</li>
<li>print "";
// output:
// Bob
?>

演示代码2：

class Person {
    private $_name;
    private $_age;
    function __set( $property, $value ) {
        $method = "set{$property}";
        if ( method_exists( $this, $method ) ) {
            return $this->$method( $value );
        }
    }

    function __unset( $property ) {
        $method = "set{$property}";
        if ( method_exists( $this, $method ) ) {
            $this->$method( null );
        }
    }

    function setName( $name ) {
        $this->_name = $name;
        if ( ! is_null( $name ) ) {
            $this->_name = strtoupper($this->_name);
        }
    }
    function setAge( $age ) {
        $this->_age = $age;
    }
}
print "";</li>
<li>$p = new Person();</li>
<li>$p->name = "bob";</li>
<li>$p->age  = 44;</li>
<li>print_r( $p );</li>
<li>unset($p->name);</li>
<li>print_r( $p );</li>
<li>print "";
?>

输出结果： Person Object ( [_name:Person:private] => BOB [_age:Person:private] => 44 ) Person Object ( [_name:Person:private] => [_age:Person:private] => 44 )