Auto-generate/loop a specific unordered list in PHP

Question

I want to make something like this:

A1
- B1
  - C1
    - D1
    - D2
    - D3
  - C2
  - C3
- B2
  - C4
    - D10
    - D11
    - D12
  - C5
  - C6
- B3
  - C7
  - C8
  - C9
    - D25
    - D26
    - D27

So it's always groups of three, with every level ascending by a letter. First level is A, second B, C, D, E and so forth. The numbers are also listed in ascending order. Level A can only reach 1, B has 3, C has 9, D has 27, and so forth.

This is really easy to generate manually, converting the letters to their ASCII equivalent, adding one and converting them to character equivalent again. Problem is, I have to loop it till S, for instance, and my mind is getting messier and messier trying to put loops within loops.

What I got (toLetter and toNumber literally does what they do):

  echo "<ul><li>";
    echo "A1";
     echo "<ul><li>";
      $b = toNumber(A);
      $b++;
      $b = toLetter($b);
      $bnum = 1 - 1;
      $bnum = $bnum * 3;
      $bnum++;

      echo $b;
      echo $bnum."</li>";
      $bnum++;
      echo "<li>".$b;
      echo $bnum."</li>";
      $bnum++;
      echo "<li>".$b;
      echo $bnum."</li>";

Making this:

A1
- B1
- B2
- B3

I really can't figure out how to just loop everything so it can reach till Z.

The first 1 should be the number of the listed item above (A1). So basically, what it does is subtract 1 from the listed item, multiply 3, then again add one to determine its own number (B1). Use it to (C6) for example to get (D16). — Another Noob
– Another Noob, Commented May 30, 2013 at 7:49
For example, we have B2 instead of A1. The right listed items under it should be C4, C5, and C6. So we take 2 from B2. 2-1=1 1*3= 3 3+1=4. That's 4 from C4. — Another Noob
– Another Noob, Commented May 30, 2013 at 7:58

deceze · Accepted Answer · 2013-05-30 08:02:43Z

3

A pretty simple version which only goes up to the 'C' level; increase as necessary.

<?php

function outputListItems($char) {
    static $index = array('A' => 1);

    if (!isset($index[$char])) {
        $index[$char] = 1;
    }

    for ($i = 0; $i < 3; $i++) {
        echo '<li>';
        echo $char;
        echo $index[$char]++;

        if ($char < 'C') {
            echo '<ul>';
            $nextChar = $char;
            outputListItems(++$nextChar);
            echo '</ul>';
        }

        echo '</li>';
    }
}

?>

<ul>
    <li>
        A1
        <ul><?php outputListItems('B'); ?></ul>
    </li>
</ul>

A is treated as special chase, since it only has one entry.

answered May 30, 2013 at 8:02

deceze♦

525k89 gold badges807 silver badges954 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Maxim Krizhanovsky · Accepted Answer · 2013-05-30 07:56:41Z

1

in PHP, you can use ++ on a string, so you don't need to Letter/toNumber And to support unlimited nesting, you need a recursion (or at least it will be easier for you)

answered May 30, 2013 at 7:56

Maxim Krizhanovsky

26.8k5 gold badges62 silver badges91 bronze badges

3 Comments

Another Noob Over a year ago

Recursion looks new to me, as I practically W3schooled myself in PHP. Where might I find more on this topic?

EaterOfCode Over a year ago

Oh god, leave w3schools it's bad. but I think this is a good explanation devzone.zend.com/283/recursion-in-php-tapping-unharnessed-power

Another Noob Over a year ago

This is one mean epic site. Thank you very much!

Collectives™ on Stack Overflow

Auto-generate/loop a specific unordered list in PHP

2 Answers 2

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related