PHP entry-level interview questions: Programming questions (1)

PHP Junior Interview Questions are for programmers with little experience who are just looking for a job. This provides a lot of help for us to go out for interview, InterviewOfficial meetings often test us, and the interview questions played a big role at this time.

1. Write a function to retrieve the file extension from a standard URL as efficiently as possible

For example: http:/ /www.php.cn/course.html Need to remove html or .html

Answer one:

function getExt($url){
   $arr = parse_url($url);
   
   $file = basename($arr['path']);
   $ext = explode(".",$file);
   return $ext[1];
}

Answer two:

function getExt($url) {
    $url = basename($url);
    $pos1 = strpos($url,".");
    $pos2 = strpos($url,"?");
    if(strstr($url,"?")){
         return substr($url,$pos1 + 1,$pos2 - $pos1 - 1);
    } else {
      return substr($url,$pos1);
    }
}

2. In HTML language, the meta tag at the head of the page can be used to output the encoding format of the file. The following is a standard meta statement

Please use PHP language to write a function to change the charset part value in a similar meta tag in a standard HTML page to big5

Please note:

• 　1. Need to process the complete html page, that is, not just this meta statement

• 　2. Ignore the case

• 3. ' and " are interchangeable here

• 4. The quotation marks on both sides of 'Content-Type' can be ignored, but the quotation marks on both sides of 'text/html; charset=gbk' It doesn’t work

• 5. Pay attention to dealing with extra spaces

3. Write a function to calculate the relative relationship between the two files Path

For example,

$a = '/a/b/c/d/e.php';
$b = '/a/b/12/34/c.php';

calculates that the relative path of $b relative to $a should be ../../c/d and add () to

Answer:

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, &#39;..&#39;));   
    }   
       
    $returnPath = array_merge($returnPath, array_slice($arrA, $n));   
    return implode(&#39;/&#39;, $returnPath);   
}   
   echo getRelativePath($a, $b);

4. Write a function that can traverse all files and subfolders in a folder.

Answer:

function my_scandir($dir)
{
     $files = array();
     if ( $handle = opendir($dir) ) {
         while ( ($file = readdir($handle)) !== false ) {
             if ( $file != ".." && $file != "." ) {
                 if ( is_dir($dir . "/" . $file) ) {
                     $files[$file] = scandir($dir . "/" . $file);
                 }else {
                     $files[] = $file;
                 }
             }
         }
         closedir($handle);
         return $files;
     }
}

Don’t worry after reading the above interview questions. There are other interview questions. It is best to consolidate the basic things to help us interview and find a job.

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