regexstringpreg-replacepreg-matchsubstr

Regex in PHP: take all the words after the first one in string and truncate all of them to the first character

I'm quite terrible at regexes.

I have a string that may have 1 or more words in it (generally 2 or 3), usually a person name, for example:

$str1 = 'John Smith';
$str2 = 'John Doe';
$str3 = 'David X. Cohen';
$str4 = 'Kim Jong Un';
$str5 = 'Bob';

I'd like to convert each as follows:

$str1 = 'John S.';
$str2 = 'John D.';
$str3 = 'David X. C.';
$str4 = 'Kim J. U.';
$str5 = 'Bob';

My guess is that I should first match the first word, like so:

preg_match( "^([\w\-]+)", $str1, $first_word )

then all the words after the first one... but how do I match those? should I use again preg_match and use offset = 1 in the arguments? but that offset is in characters or bytes right?

Anyway after I matched the words following the first, if the exist, should I do for each of them something like:

$second_word = substr( $following_word, 1 ) . '. ';

Or my approach is completely wrong?

Thanks

ps - it would be a boon if the regex could maintain the whole first two words when the string contain three or more words... (e.g. 'Kim Jong U.').

Solution

  • It can be done in single preg_replace using a regex.

    You can search using this regex:

    ^\w+(?:$| +)(*SKIP)(*F)|(\w)\w+

    And replace by:

    $1.

    RegEx Demo

    Code:

    $name = preg_replace('/^\w+(?:$| +)(*SKIP)(*F)|(\w)\w+/', '$1.', $name);

    Explanation: