php数组的升维和降维处理

//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;
}