How do I split a string up into an Array of 1 and 2 character

[james909]

I have the following alpha-numeric example string

$string = "1AJ4dH4c2bRfa6";

which I want my php to split upto in the following array, into 1 characters, unless the character is a lower case a,b,c or d then i want the following character to be added to that array value:

stringarray[1] = "1";
stringarray[2] = "A";
stringarray[3] = "J";
stringarray[4] = "4";
stringarray[5] = "dH";
stringarray[6] = "4";
stringarray[7] = "c2";
stringarray[8] = "bR";
stringarray[9] = "f";
stringarray[10] = "a6";

The string that needs splitting up could be longer or shorter than this example.

 

I have tried string split, but this can only split the string into array value lengths of 1 or 2, not how I want:

$stringarray = str_split($string, 1);
$stringarray = str_split($string, 2);

What is the code for: if the charater is aphanumeric (1-0 A-Z a-z) I need the it to be split into an array value of 1 character, with the exception of if the character is lower case a, b, c or d then the next character needs to be added to that array value.

Edited July 17, 2013 by james909

[requinix]

Think of it less like splitting the string and more like finding all the characters and pairs of characters. How to do that?

 

Reeegulaaar expreeessions. With preg_match_all().

preg_match_all('/[abcd]?./', $string, $matches); // and use $matches[0]

[gizmola]

requinix provided a great solution with regex.  

 

Just for the fun of it, I tried to whip up a quickie function and this one would also do the job.  I provide it purely for amusement:

 

<?php

$string = "1AJ4dH4c2bRfa6";

function my_split($string) {
  $size = strlen($string);
  $result = array();
  $t = '';
  for ($i = 0; $i < $size; $i++) {
    if ($string[$i] >= 'a' and $string[$i] <= 'd') {
        $t = $string[$i];
    } else {
        $t .= $string[$i];
        $result[] = $t;
        $t = '';
    }
  }
  return $result;
}

var_dump(my_split($string));

[james909]

thank you requinix preg_match_all is working nicely.

 

and also thank you gizmola, always good to have a back up function if the version of php doesn't support preg_match_all