写一个函数，算出两个文件的相对路径 　　如 $a = '/a/b/c/d/e.php'; 　　$b = '/a/b/12/34/c.php'; 　　计算出 $b 相对于 $a 的相对路径应该是 ../../c/d将()添上 答:function getRelativePath($a, $b) { $returnPath = array(dirname($b)); $arrA = explode('/', $a); $arrB = explode('/', $returnPath[0]); for ($n = 1, $len = count($arrB); $n < $len; $n++) { if ($arrA[$n] != $arrB[$n]) { break; } } if ($len - $n > 0) { $returnPath = array_merge($returnPath, array_fill(1, $len - $n, '..')); } $returnPath = array_merge($returnPath, array_slice($arrA, $n)); return implode('/', $returnPath); } echo getRelativePath($a, $b); count($arrB); $n < $len; $n++) { if ($arrA[$n] != $arrB[$n]) { break; } } if ($len - $n > 0) { $returnPath = array_merge($returnPath, array_fill(1, $len - $n, '..')); } $returnPath = array_merge($returnPath, array_slice($arrA, $n)); return implode('/', $returnPath); } echo getRelativePath($a, $b);