如何创建无限功能循环？ （PHP）

Question

Here's the actual function

$linkArray = array(//associative array for title and url of site and etc
        "url"=>"",
        "title"=>"",
        "num"=>""
    );
    $site = $_POST['link'];
    function parseLink($link){
        global $conn;//reinitialize conn variable b/c inside fn it's unknown unless reinitialized       
        //get title of page
        $page_title = get_url_title($link);
        //1-Get HTML content
        $html = file_get_contents($link);
        $a_tag = preg_match_all('/<a[^>]+>/i', $html, $result);
        $i = 0;//dummy var
        //check if we get result
        if($a_tag > 0){
            while($i < $a_tag){
                $alink = $result[0][$i];
                preg_match_all('/(href)=("[^"]*")/i',$alink, $href);
                $hreflnk = $href[0][0];
                $hreflnk = str_replace('href="',"",$hreflnk);
                $hreflnk = substr($hreflnk, 0, -1);
                //filter out only links that start with http -> this will automatically include https
                //$randomvar = preg_match("/^http/i",$hreflnk,$outp);
                if(preg_match("/^http/i",$hreflnk)){
                    $hreflnk = $hreflnk;
                } else{
                    //idk
                    $hreflnk = '';
                }
                $linkArray['url'][$i] = $hreflnk;
                $linkArray['title'] = $page_title;
                $linkArray['num'] = $a_tag;

                $siteTitle = $linkArray['title'];
                $numLinks = $linkArray['num'];
                $siteUrl = $linkArray['url'][$i];
                $queryI = $conn->query("INSERT INTO data (title, url, numLinks) VALUES ('$siteTitle','$siteUrl','$numLinks')");
                $outLink = $linkArray['url'][0];
                $i++;
            }

        }

        return $outLink;
    }

This function takes in a URL searches through the HTML and stores all http links in array and later uploads them to a db. Before it ends it returns the first link of all of those that were collected. So what I want to do is run that link back into this function. Then this process will repeat.

Answer 1

Just use a recursive function:

function foo($i = 0) {
    if ($i == 100) {
        return 'yay';
    } else {
        $i++;
        return foo($i);
    }
}
foo();

Alternatively, do you really need a repeating function?

$i = 0;
while($i != 100) {
    $i++;
}

or:

$i = 0;
do {
    $i++;
} while ($i != 100);

With a string:

do {
    $recordString = DB::get()->getRow('SELECT `name` from `username` ORDER BY RAND()')->getField('name');
} while ($recordString != 'admin') {

//$recordString will now 100% be 'admin', unless you time out during the execution

Edit :

With your new question update, I'd propose you to change your code to the following:

<?php
    function parseLink($link, $outLinks = array()){
        global $conn;//reinitialize conn variable b/c inside fn it's unknown unless reinitialized       
        //get title of page
        $page_title = get_url_title($link);
        //1-Get HTML content
        $html = file_get_contents($link);

        $document = DOMDocument::loadHTML($html);
        foreach ($document->getElementsByTagName('a') as $element) {
            $href = $element->getAttribute('href');

            if (!isset($outLinks[$href])) { //don't redo ones we've already done
                $linkArray['url'][$i] = $href;
                $linkArray['title'] = $page_title;
                $linkArray['num'] = $i;

                $siteTitle = $linkArray['title'];
                $numLinks = $linkArray['num'];
                $siteUrl = $linkArray['url'][$i];
                $queryI = $conn->query("INSERT INTO data (title, url, numLinks) VALUES ('$siteTitle','$siteUrl','$numLinks')");
                $outLinks[$href] = $linkArray['url'][0];
                $i++;
            }
        }

        foreach ($outLinks as $href => $dbID) {
            $outsLinks = parseLink($href, $outLinks);
        }

        return $outLinks;
    }
?>

Changes :

• Used DOMDocument instead, as regex shouldn't be used to parse HTML.
• Changed $outLink to use the array $outLinks which it returns.

Answer 2

while($myvar) $myvar = test($myvar);

Answer 3

Please try this:

$value = "Initial value";

function test($input){
  // does stuff inside
  // sets output to false if blank
  return $output;
}

while($value) {
  // runs until test returns false or an empty string
  $value = test($value);
}