Odtnhj

I would like to capitalize the first letter after a dot or after a dot and a space.

$string="I am a string with several periods.period #1. period #2.";

This should be the final string:

I am a string with several periods.Period #1. Period #2.

I have already searched for a solution on stackoverflow but the solution that i found was only for capitalize the initial letter after just a dot and not for a dot and a space.

Use regex to match the dot ., optional space s* and a letter w.

Then loop the matches array and do a str_replace.

$str="I am a string with several periods.period #1. period #2.";
preg_match_all("/.s*w/", $str, $matches);

foreach($matches[0] as $match)
 $str = str_replace($match, strtoupper($match), $str);

echo $str;
//I am a string with several periods.Period #1. Period #2.

https://3v4l.org/LevU5

To make it slightly more optimized you could add an array_unique before looping since str_replace replaces all equal substrings.

$matches[0] = array_unique($matches[0]);

https://3v4l.org/mIiX8

Preg_replace_callback is your friend:

$string="I am a string with several periods.period #1. period #2.";
$string = preg_replace_callback('/.s*Kw/', 
 function($m) 
 return strtoupper($m[0]);
 ,
 $string);
echo $string; 

Output:

I am a string with several periods.Period #1. Period #2.

If regex is not an option, something like this might work:

$str = "I am a string with several periods.period #1. period #2.";
$strings = explode('.', $str);
$titleCased = ;

foreach($strings as $s)
 $titleCased = ucfirst(trim($s));

echo join(".", $titleCased);

Although, this has the added effect of removing whitespace.

https://3v4l.org/fWGUW

I created this simple function and it works like a charm

and you can add delimiters as you like.

function capitalize_after_delimiters($string='', $delimiters = array())

 foreach ($delimiters as $delimiter)
 
 $temp = explode($delimiter, $string);
 array_walk($temp, function (&$value) $value = ucfirst($value); );
 $string = implode($temp, $delimiter);
 
 return $string;


$string ="I am a string with several periods.period #1. period #2.";

$result = capitalize_after_delimiters($string, array('.', '. '));

var_dump($result);

result: string(56) "I am a string with several periods.Period #1. Period #2."

result