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php递归用法与递归目录实例

WBOY
WBOYOriginal
2016-06-08 17:23:171336browse

在php中递归算法是我们比得不多的一种数据遍历方式了，下面我来给大家介绍一下利用递归来做一下用的东西吧。

<script>ec(2);</script>

看一个简单的递归实例

例1

 代码如下 复制代码

function demo($a) { 

    static $sum=1; 

    if($a > 1){ 

        $sum*=$a; 

        demo(--$a); 

    }else{ 

        $a=$sum; 

        } 

        return $sum; 

} 
 

echo demo(10);

例2

遍历目录

 代码如下 复制代码

class listdir{
var $depth;
var $dirname;
var $list;
var $tostring;

function listdir($dir){
$this->dirname=$dir;
$this->depth=0;
$this->tostring=”";
}

//把结果保存进多维数组
function getlist($dir=”"){
if($dir==”")$dir=$this->dirname;
$d=@dir($dir);
while(false!==($item=$d->read()))
{
if($item!=”.”&&$item!=”..”)
{
$path=$dir.”/”.$item;
if(is_dir($path)){
$this->depth+=1;
$this->getlist($path);
}else{
$this->list[$this->depth][]=$item;
}
}
}
$this->list[$this->depth]['directory']=$dir;
$this->depth-=1;
$d->close();
return $this->list;
}

//字符窜化结果

function tostring($dir=”"){
if($dir==”")$dir=$this->dirname;
$d=@dir($dir);
$this->tostring.=”

    n”;
    $this->tostring.=”Directory:”.$dir.”n”;
    while(false!==($item=$d->read()))
    {
    if($item!=”.”&&$item!=”..”)
    {
    $path=$dir.”/”.$item;
    if(is_dir($path)){
    $this->depth+=1;
    $this->tostring($path);
    }else{
    $this->tostring.=”
  • ”.$item.”
    • n”;
    }
    }
    }
    $this->depth-=1;
    $d->close();
    $this->tostring.=”
n”;
return $this->tostring;
}
}
$wapdir=”jquery”;
$d=new listdir($wapdir);
echo $d->tostring();
?>

输出结果：


    Directory:jquery
  • jquery-1.3.2.js

  • jquery-1.3.2.min.js

  • jquery-1.3.2-vsdoc2.js

  • test.html

  • common.js


      • Directory:jquery/d
    • common.js

    • jquery-1.3.2.js
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