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Home Backend Development PHP Tutorial php子类重载父类私有方法的疑问

php子类重载父类私有方法的疑问

Jun 20, 2016 pm 12:29 PM

<?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);?>
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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);?>
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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;        }}
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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;    $var1->test(10);?>
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而下面这段代码在子类中,如果是重写,那么为什么参数列表不一致正确呢?
<?php	class A{		private function test(){			echo "testA";		}	}	class B extends A{		private function test($a){			echo "testB".$a;		}		public function test1($a){			$this->test($a);		}	}		$var1=new B;	$var1->test1(10);?>
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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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