转换数组中替换的字符串

I have the following code:

<?php
$text = 'Hey @Mathew, have u talked with @Jhon today?';
    $text = preg_replace('/(^|\s)@([A-Za-z0-9]*)/', '\1<a href="profile.php?user=\\2">@\\2</a>',$text);
?>

And my goal is notify the user was quoted. To do that, I thought: I put all the replaced strings in a array and pick only the name; using the example above, and following the thinking, I have this result:

['Mathew', 'Jhon']

So, how can I have the last result?

You may actually collect matches while performing a regex-based search and replace if you use preg_replace_callback:

$text = 'Hey @Mathew, have u talked with @Jhon today?';
$names = [];
$text = preg_replace_callback('/(^|\s)@([A-Za-z0-9]*)/', function($m) use (&$names) {
        $names[] = $m[2];
        return $m[1] . '<a href="profile.php?user=' . $m[2] . '">@' . $m[2] . '</a>';
    },$text);
echo "$text
";
print_r($names);

See the PHP demo

Output:

Hey <a href="profile.php?user=Mathew">@Mathew</a>, have u talked with <a href="profile.php?user=Jhon">@Jhon</a> today?
Array
(
    [0] => Mathew
    [1] => Jhon
)

Note the array variable for the matches is passed to the anonymous function with the use (&$names) syntax. The $m is a match object containing the whole match in the first item and captures in the subsequent items.

Before replacing the text you can use preg_match to find all users in the string:

http://php.net/manual/en/function.preg-match.php

Example:

$text = 'Hey @Mathew, have u talked with @Jhon today?';

preg_match($pattern, $text, $matches);
var_dump($matches);

$text = preg_replace('/(^|\s)@([A-Za-z0-9]*)/', '\1<a href="profile.php?user=\\2">@\\2</a>',$text);

You will have to alter your pattern for this to work.

I guess you can use a regex like /@[a-z0-9]+/sim, i.e.:

$text = 'Hey @Mathw, have u talked with @Jhon today?';
preg_match_all('/@[a-z0-9]+/sim', $text , $handles_array, PREG_PATTERN_ORDER);
$text = preg_replace('/(@[a-z0-9]+)/sim', '<a href="profile.php?user=$1">$1</a>', $text);
print($text);
print_r($handles_array[0]);

Output:

Hey <a href="profile.php?user=@Mathw">@Mathw</a>, have u talked with <a href="profile.php?user=@Jhon">@Jhon</a> today?Array
(
    [0] => @Mathw
    [1] => @Jhon
)

Live Demo:

https://ideone.com/oU6xbb

Note:

"It's an example of array..."

I'm not aware of any programing language which arrays are declared with curly brackets {}, objects normally are. Did you mean brackets []?