php递归函数怎么用才有效？php递归函数典型例子

function test(){
    static $dig=0;
    if($dig++<10){
        echo $dig;
        test();
    }
}
test();//12345678910

function unreverse($str){
    for($i=1;$i<=strlen($str);$i++){
        echo substr($str,-$i,1);
    }
}
unreverse("abcdefg");//gfedaba
function reverse($str){
    if(strlen($str)>0){
        reverse(substr($str,1));
        echo substr($str,0,1);
        return;
    }
}
reverse("abcdefg");//gfedaba

//递归获得角色ID字符串
function explodeRole($roleObj, &$resultStr){
  if(0 < count($roleObj->childRoleObjArr)){
    foreach($roleObj->childRoleObjArr as $childRoleObj){
      if('' == $resultStr){
        $resultStr .= "{$childRoleObj->id}";
      }else{
        $resultStr .= ", {$childRoleObj->id}";
      }
      explodeRole($childRoleObj, $resultStr);
    }
  }
}
 
//递归获取级联角色信息数组
function makeRoleRelation(&$roleObjArr){
  foreach($roleObjArr as $item){
    $item->childRoleObjArr = getRoleObjArrByParentId($item->id);
    if(0 < count($item->childRoleObjArr)){
      makeRoleRelation($item->childRoleObjArr);
    }
  }
}
 
//通过父角色的id获取子角色信息  
function getRoleObjArrByParentId($parentid){
  $operCOGPSTRTSysRole = new COGPSTRTSysRole();
  $operCOGPSTRTSysRole->setColumn($operCOGPSTRTSysRole->getAllColumn());
  $operCOGPSTRTSysRole->setWhere("parentroleid={$parentid}");
  $roleObjArr = $operCOGPSTRTSysRole->convResult2ObjArr($operCOGPSTRTSysRole->selectTable());
  return isset($roleObjArr)?$roleObjArr:array();
}

function test(){
  static $dig=0;
  if($dig++<10){
    echo $dig;
    test();
  }
}
test();//12345678910

 function unreverse($str){ 
 for($i=1;$i<=strlen($str);$i++){ 
 echo substr($str,-$i,1); 
 } 
 } 
 unreverse("abcdefg");
 //gfedaba
 function reverse($str){ 
 if(strlen($str)>0){
 reverse(substr($str,1)); 
 echo substr($str,0,1); return; 
 } 
 } 
 reverse("abcdefg");//gfedaba

0) reverse_r(substr($str,1)); echo substr($str,0,1); return; } ?>