你知道Thinkphp5中this关键字的用法？

<?php
class UserName
{
//定义属性
private $name;
//定义构造函数
function construct( $name ){
$this->name = $name; //这里已经使用了this指针
}
//析构函数
function destruct(){}
//打印用户名成员函数
function printName(){
print( $this->name ); //又使用了this指针
}
}
//实例化对象
$nameObject = new UserName( "heiyeluren" );
//执行打印
$nameObject->printName(); //输出: heiyeluren
//第二次实例化对象
$nameObject2 = new UserName( "PHP5" );
//执行打印
$nameObject2->printName(); //输出：PHP5
?>

<?php
class Counter
{
//定义属性，包括一个静态变量
private static $firstCount = 0;
private $lastCount;
//构造函数
function construct(){
$this->lastCount = ++selft::$firstCount; //使用self来调用静态变量,使用self调用必须使用::(域运算符号)
}
//打印最次数值
function printLastCount(){
print( $this->lastCount );
}
}
//实例化对象
$countObject = new Counter();
$countObject->printLastCount(); //输出 1
?>

<?php
//基类
class Animal
{
//基类的属性
public $name; //名字
//基类的构造函数
public function construct( $name ){
$this->name = $name;
}
}
//派生类
class Person extends Animal //Person类继承了Animal类
{
public $personSex; //性别
public $personAge; //年龄
//继承类的构造函数
function construct( $personSex, $personAge ){
parent::construct( "heiyeluren" ); //使用parent调用了父类的构造函数
$this->personSex = $personSex;
$this->personAge = $personAge;
}
function printPerson(){
print( $this->name. " is " .$this->personSex. ",this year " .$this->personAge );
}
}
//实例化Person对象
$personObject = new Person( "male", "21");
//执行打印
$personObject->printPerson(); //输出：heiyeluren is male,this year 21
?>