关于set的问题
class aa{ function __set($pro, $v){ echo "a\n"; $this->pro=$v; echo "$v\n"; }}$a=new aa;$a->b=1;
输出是a a 1 1;
2个问题,为何输出2次;
为何是a a 1 1,而不是a 1 a 1;
回复讨论(解决方案)
你把 echo "a\n"; 改成 echo "$pro\n"; 就会看到
b 因为 b 属性不存在,所以进入了 __set 方法
pro 同样因为 pro 属性不存在,再次进入 __set 方法
1 进入两次,打印两次值就不足为奇了
1
当 $this->pro=$v;
改为 $this->$pro=$v;
就只进入一次了
你把 echo "a\n"; 改成 echo "$pro\n"; 就会看到
b 因为 b 属性不存在,所以进入了 __set 方法
pro 同样因为 pro 属性不存在,再次进入 __set 方法
1 进入两次,打印两次值就不足为奇了
1
当 $this->pro=$v;
改为 $this->$pro=$v;
就只进入一次了
理解了,主要是$this->pro的问题;
平时手误写成$this->$val,会被提示未定义变量; 没注意魔术方法里面就是这样用的;

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