How to compare one string with many others?

[Gary_King]

I have one string, called $a[0] . I have 10 other strings, called $a[1] all the way up to $a[10] (so 10 more vars - 11 in total).

Let's say:

$a[0] = 'abcdabcdabcd';
$a[1] = 'aabbaabbaab';
$a[2] = 'abcabcabcabc';
$a[3] = 'dcbadcbadcba';
$a[4] = 'abccabcdaccd';

// and the remaining variables are also random, using only abcd and having the same # of letters

How can I compare the $a[0] with the other vars to see which ones match the closest (and taking the order of the letters into consideration as well)? For example, $a[4] is obviously closest to $a[0], because it's the same thing, except for the 2 characters that have been changed to 'c' instead. The other strings surely have more than 2 differences, so they are ruled out and $a[4] will be taken as the closest one.

How can I do this using PHP?

Thanks in advance! 🙂

[Frederick]

All I can come up with is this:

<?php
$array1 = array();
array_push($array1,'abcdabcdabcd');
array_push($array1,'aabbaabbaab');
array_push($array1,'abcabcabcabc');
array_push($array1,'dcba668cba');
array_push($array1,'abccabcdaccd');

$array2 = array();
array_push($array2,'abcdabcdabcd');
array_push($array2,'aabbaatt2');
array_push($array2,'abcabcabcabc');
array_push($array2,'dcbadcbadcba');
array_push($array2,'abccabcdaccd');

$result = array_diff ($array1, $array2);

print_r($result);
?>

Results are:

Array ( [1] => aabbaabbaab [3] => dcba668cba )

[drew010]

you may want to decide which of these two algorithms is closer to what you are trying to do:
[man]levenshtein[/man]
and
[man]similar_text[/man]

i think levenshtein is probably just what you are looking for though.