REGEX：如何匹配后跟空格并包含特定字符/符号的字符串

Question

i have the following string

string string#string#string string
string$string (string) string string string
string string#gulaen#string string-stringan 
(string) string#string#string$string string string (string)
string string string$string#string$string#string string
string string#string$string#string string
string#string$string#string string

with this pattern /\\b(\\w+[\\#\\$])\\w+\\b/ i try to match string that followed by space and contains # and $ but i can't get the result that i want. i get the folowing result

what i expect is to match the following highlighted blue:

how to achieve that? thanks

Answer 1

You may create a group that will match the special symbol and 1+ word chars, and quantify it with + :

/\b\w+(?:[#$]\w+)+\b/

See the regex demo

The pattern matches:

• \\b - a word boundary
• \\w+ - 1+ word chars
• (?:[#$]\\w+)+ - a non-capturing group that matches 1 or more consecutive occurrences of a # or $ chars followed with 1+ word chars
• \\b - a word boundary.

See the PHP demo :

echo preg_replace('/\b\w+(?:[#$]\w+)+\b/u', '<span>$0</span>', $str);

Output for the $str in question:

string <span>string#string#string</span> string
<span>string$string</span> (string) string string string
string <span>string#gulaen#string</span> string-stringan 
(string) <span>string#string#string$string</span> string string (string)
string string <span>string$string#string$string#string</span> string
string <span>string#string$string#string</span> string
<span>string#string$string#string</span> string

Matching code demo :

if (preg_match_all('/\b\w+(?:[#$]\w+)+\b/u', $str, $m)) {
    print_r($m[0]);
}

Output:

Array
(
    [0] => string#string#string
    [1] => string$string
    [2] => string#gulaen#string
    [3] => string#string#string$string
    [4] => string$string#string$string#string
    [5] => string#string$string#string
    [6] => string#string$string#string
)