I have a system for posting content on a certain social network of our company.
When the user enters text with hashtags , I need to detect all of them and store them in an array.
Example:
Hello, I'm posting this # question to #stackoverlow. I hope you find good answers.
I want you to return:
array('pergunta', 'stackoverlow', 'respostas');
Remember that if the hashtag contains accented characters, they must also be processed.
Example:
#notícias
#sãoPaulo
I believe that this regex solves the problem, the combination of% w / o% is followed by any character in the range of (az, 0-9), the% w /% parameter means that the combination will be case insensitive, # add character support with multibyte.
<?php
$str = '#pergunta no #stackoverlow #notícias 2015 #sãoPaulo';
preg_match_all('/#\w+/iu', $str, $itens);
echo "<pre>";
print_r($itens);
Output:
Array
(
[0] => Array
(
[0] => #pergunta
[1] => #stackoverlow
[2] => #notícias
[3] => #sãoPaulo
)
)
i from caputra, @Guilherme Lautert suggested changing the regex to: u , using Lookbehind positive, which checks if the character exists but does not capture it.
Recommended reading
Using the comment from @renan.
A changing the answer given:
$tweet = "this has a #hashtag a #badhash-tag and a #goodhash_tag";
preg_match_all("/(#[^ #]+)/", $tweet, $matches);
var_dump( $matches );
So it looks for anything except " " (space), and the actual # , which has # ahead.
Another way is to regex the hashtag tag and separate only the group with:
function extractTags($mensagem)
{
// Casa tags como #dia #feliz #chateado
// Não casa caracteres especias #so-pt
$pattern = '/#(\w+)/u';
// Alternativa para incluir outros caracteres
// Basta incluir entre os colchetes
//$pattern = '/#([\w-]+)/u';
preg_match_all($pattern, $mensagem, $tags);
// Utiliza o vetor com os grupos capturados entre parenteses
return $tags[1];
}
Extract this function from a response I gave earlier in another question: System hashtags in PHP
In PHP you use the preg_replace function, with the regex below, it will fetch all words that contain # and return in matches
preg_replace('/\#[A-Za-z-0-9]+/m',$string,$matches);
var_dump( $matches );