//假设有数组降维前，如下$array = array(	‘a‘ => array(		‘b‘ => 1,		‘c‘ => array(			‘d‘ => 2,			‘e‘ => 3		)	),	‘f‘ => 4,	‘g‘ => array(		‘h‘=>5			)	);

//降维后$array = array(    ‘0‘ => a->b->1,    ‘1‘ => a->c->d->2,    ‘2‘ => a->c->e->3,    ‘3‘ => f->4,    ‘4‘ => g->h->5);

/** * 将多维数组降维成一维数组，递归实现 * @param unknown $arr * @param string $delimiter * @param string $key * @return boolean|Ambigous <multitype:string , multitype:> */function multiToSingle($arr, $delimiter = ‘->‘,$key = ‘ ‘) {	$resultAry = array();	if (!(is_array($arr) && count($arr)>0)) {		return false;	}	foreach ($arr AS $k=>$val) {		$newKey = trim($key . $k . $delimiter);		if (is_array($val) && count($val)>0) {			$resultAry = array_merge($resultAry, multiToSingle($val, $delimiter, $newKey));		} else {			$resultAry[] = $newKey . $val;		}	}	return $resultAry;}

/** * 将一维数组升维成多维数组 * @param unknown $arr * @param string $delimiter * @return multitype: */function singleToMulti($arr, $delimiter = ‘->‘){	$endAry = array();	foreach ($arr AS $key=>$val) {			$sAry = explode($delimiter, $val);		$len = count($sAry);		$ary = array();		for ($i=$len-2; $i>-1; $i--) {			if ($i == $len-2) {				$ary[$sAry[$i]] = $sAry[$i+1] ;			} else {				$ary = array($sAry[$i] => $ary);			}		}		$endAry = array_merge_recursive($endAry, $ary);	}	return $endAry;}