Extraction

Match a hashtag

Flags: g

Extract hashtags (#topic) from social media style text.

Pattern

Regular expression

#\w+

Matches `#` followed by one or more word characters. Simple and effective for latin-alphabet hashtags.

For non-Latin hashtags (Chinese, Arabic, emoji), use the Unicode-aware pattern: `#[\p{L}\p{N}_]+` with the `u` flag in JS.

JavaScript

const re = /#\w+/g;
"#dev #webdev".match(re); // ["#dev", "#webdev"]

Python

re.findall(r"#\w+", "#dev #webdev")

re := regexp.MustCompile(`#\w+`)
re.FindAllString("#dev #webdev", -1)

Java

Pattern.compile("#\\w+")

Match an @-mention

@[A-Za-z0-9_]{1,39}

Extract a URL query parameter

[?&]KEY=([^&#]*)

Match a quoted string

"(?:[^"\\]|\\.)*"

Match an HTML tag

<\/?[A-Za-z][A-Za-z0-9]*\b[^>]*>