子类使用父类变量解决思路

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Release: 2016-06-13 10:21:38
Original
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子类使用父类变量
class A {
var $authKey='1111';

}

class B extends A{
 __construct(){
  echo parent::authKey;
}
}
报错Undefined class constant 'authKey'

------解决方案--------------------
错误信息的意思是未定义的常量。你少了个$
但$authKey不是静态变量,所以你不能这么静态调用
正确的做法

PHP code
class A {   // 不建议类中用var来声明变量   public $authKey='1111';}class B extends A{   // B将拥有A的所有非private成员   public function __construct(){      echo $this->authKey;   }}<br><font color="#e78608">------解决方案--------------------</font><br>var 是在php4以前的版本,后来就省略了。<br><font color="#e78608">------解决方案--------------------</font><br>var最好还是视情况带上!有些低版本支持<br><font color="#e78608">------解决方案--------------------</font><br>var 是php 4.X中的,,,5+里使用是为了向下兼容,,<br><br>新写的程序,基本可以放弃这种写法了<br><br>你的代码也可以这样用<br>
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PHP code
class A {const authKey='1111';}class B extends A{ public function __construct(){  echo parent::authKey;}}new B;<div class="clear">
                 
              
              
        
            </div>
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