PHP面试题：写一个函数，算出两个文件的相对路径，4种方法

//在网上搜了4种答案，结果都不一样，请问哪个是对的？还是都不对，您有好的解决办法吗？求//解!!! ?php header("content-type:text/html;charset=utf-8"); $a='/a/b/c/d/e.php'; $b='/a/b/12/34/c.php'; function getRelativePath($a, $b) {///a/b/12/34/..

//在网上搜了4种答案，结果都不一样，请问哪个是对的？还是都不对，您有好的解决办法吗？求//解!!!

header("content-type:text/html;charset=utf-8");
$a='/a/b/c/d/e.php';
$b='/a/b/12/34/c.php';
function getRelativePath($a, $b) {///a/b/12/34/../../c/d/e.php
$returnPath = array(dirname($b));
$arrA = explode('/', $a);
$arrB = explode('/', $returnPath[0]);
for ($n = 1, $len = count($arrB); $n if ($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);
//输出结果：/a/b/12/34/../../c/d/e.php
echo "

---

";

function getRelativePath1($a,$b){
$a_url = array(dirname($a));
$b_url = array(dirname($b));
$a_arr = explode('/',$a_url[0]);
$b_arr = explode('/',$b_url[0]);
$len = count($a_arr);
$art1 = '';
$art2 = '';
for($i=1;$i if($a_arr[$i]$b_arr[$i]){
$art1.= '../';
$art2.= $a_arr[$i].'/';
}
}
return $art1.$art2;
}
echo getRelativePath1($a, $b);
//输出结果：../../c/d/
echo "

---

";


function getpathinfo( $a, $b ) {
$a2array = explode('/', $a);
$b2array = explode('/', $b);
$pathinfo = '';
for( $i = 1; $i $pathinfo.=$a2array[$i] == $b2array[$i] ? '../' : $b2array[$i].'/';
}
print_R($pathinfo);
}
getpathinfo($a, $b);
//输出结果：../../12/34/
echo "

---

";


$path="";
$path1 = explode('/',dirname($a));
$path2 = explode('/',dirname($b));
$aLen = count($path1);
$bLen = count($path2);
$maxLen = max($aLen,$bLen);
for($i = 1; $i if($path1[$i] != $path2[$i] && isset($path1[$i])){
if(isset($path2[$i]))$bUrl[]=$path2[$i];
$path.= "../";
}else{
$bUrl[]=$path2[$i];
}
}
echo $path.implode('/',$bUrl).'/'.basename($b);

//输出结果：../../a/b/12/34/c.php
?>