php子类重载父类私有方法的疑问
<?php class A{ private function test(){ echo "testA"; } } class B extends A{ public function test($a){ echo "testB".$a; } } $var1=new B; $var1->test(10);?>
上述代码中:
子类B虽然继承了A,但是A中的test()是私有方法,原则上应该是不会被继承的,为什么在B中定义一个同名但是参数不同的test()会报错呢,这也算是重载的错误吗?
回复讨论(解决方案)
<?php class A{ private function test(){ echo "testA"; } } class B extends A{ private function test($a){ echo "testB".$a; } public function test1($a){ $this->test($a); } } $var1=new B; $var1->test1(10);?>
而将B中的public该为private就不会报错
你看看错误信息不就知道怎么回事了吗?
你看看错误信息不就知道怎么回事了吗?
我知道错误的原因是重写,但是有两个疑问:
1.父类的private方法不是不会被继承吗,为什么会导致重写?
2.为什么子类中public和protected会报错,而private不会报错?
class B extends A{ public function test($a){ echo "testB".$a; }}
能麻烦解释一下吗?
不是重写,是覆盖
覆盖的条件是保护方式和参数一致
这种从 java 硬拽过来的玩意,违背了 php 的初衷,并最终导致 php 的死亡
连 C# 都在推出“动态语言”了,php 还逐步静态化,这不是倒退吗?
不是重写,是覆盖
覆盖的条件是保护方式和参数一致
这种从 java 硬拽过来的玩意,违背了 php 的初衷,并最终导致 php 的死亡
连 C# 都在推出“动态语言”了,php 还逐步静态化,这不是倒退吗?
重写和覆盖不是一个意思吗?
可能我没表达清楚,我的意思是父类中的private test()方法不是不可以继承吗,那么在子类中理论上我可以起一个名为test()的函数,并且参数列表也是任意的,可是这段代码会报错。 所以是不是不能继承的方法也存在重写?
<?php class A{ private function test(){ echo "testA"; } } class B extends A{ public function test($a){ echo "testB".$a; } } $var1=new B; $var1->test(10);?>
而下面这段代码在子类中,如果是重写,那么为什么参数列表不一致正确呢?
<?php class A{ private function test(){ echo "testA"; } } class B extends A{ private function test($a){ echo "testB".$a; } public function test1($a){ $this->test($a); } } $var1=new B; $var1->test1(10);?>
B::test 是重新定义,或是说是重写(覆盖)
重载,在 php 中是不支持的
至于说那些所谓的语法检查,那都是胡扯的,硬拽进来拖慢 php 速度用的
B::test 是重新定义,或是说是重写(覆盖)
重载,在 php 中是不支持的
至于说那些所谓的语法检查,那都是胡扯的,硬拽进来拖慢 php 速度用的
就是说B::test()跟父类没有半毛钱关系对吧,谢谢了。
对的,对的,对的
B::test 是重新定义,或是说是重写(覆盖)
重载,在 php 中是不支持的
至于说那些所谓的语法检查,那都是胡扯的,硬拽进来拖慢 php 速度用的
或者说此处不存在重写,只是在B类中定义了一个新的函数test()而已。
但形式上是重写了

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