Iterator while迭代
最后更新于：2022-04-02 02:26:21
[TOC]
## 实例
```
class demo implements Iterator {
public $a=[1,2,3,4];
public $index=0;
public function current(){
return $this->index;
}
public function next(){
$this->index++;
return $this->a[$this->index];
}
public function key(){
return $this->index;
}
public function valid(){
return isset($this->a[$this->index]);
}
public function rewind(){
return $this->index=0;
}
}
$demo =new demo();
// 使用 foreach
//foreach ($demo as $k=>$v){
// var_dump($v);
//}
// 使用 while
while($demo->valid()){
var_dump($demo->current());
$demo->next();
}
```
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