Simple regex on string

I’m working on a simple mention system and in my PHP script and I need to extract client:6 from the larger text where one or more @mention like @[John Doe (#6)](client:6) will be present.

Ex. This is my text how do you like it @John and do you have any thoughts @Jane

In php the string will look like.

This is my text how do you like it @[John Doe (#6)](client:6) and do you have any thoughts @[Jane Doe (#7)](client:7)

and i need to get an array with array('client:6','client:7')

Answer

One of many possible ways would be

@[[^][]+]s*(K[^()]+

See a demo on regex101.com.

---

In terms of regular expressions, this boils down to

@          # "@" literally
[         # "[" literally
[^][]+     # not "[" nor "]" as many times as possible
]s*      # followed by "]" literally + whitespaces, eventually
(         # you name it - "(" literally
K         # forget all what has been matched that far
[^()]+     # not "(" nor ")"

---

In PHP this could be

<?php

$data = "This is my text how do you like it @[John Doe (#6)](client:6) and do you have any thoughts @[Jane Doe (#7)](client:7)";

$regex = "~@[[^][]+]s*(K[^()]+~";

preg_match_all($regex, $data, $matches);

print_r($matches);

?>

And would yield

Array
(
    [0] => Array
        (
            [0] => client:6
            [1] => client:7
        )

)

See a demo on ideone.com.