php面向对象的有关问题
Jun 13, 2016 pm 12:09 PM
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php面向对象的问题
请看下面一段代码,非常简单,请大家花点时间看看:
<br />class person{ <br /> public $name;<br /> public function __construct(){<br /> $this->$name='Tom'; //代码1<br /> }<br />}<br />$a=new person();<br />echo $a->name;<br />
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运行上面这段代码,会报一个'变量未定义'的错误.
请问为什么会报这个错误?
如果把代码1换成 $this->name='Tom',就不会报错
请问这里的美元符号有什么特殊意义吗?没有美元符号和有美元符号有什么区别?
谢谢.
------解决思路----------------------
那么你说说看:
$name 和 $$name 的区别
------解决思路----------------------
$this->name 类的name属性
$this->$name 类的$name 属性,由于你没先定义变量$name ,所以当然要报错了。
------解决思路----------------------
可变变量
如果$name = 'hello'
$this->$name 相当于 $this->hello
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