regex101: JavaScript Match Workspace

Pro

Negative Lookbehind(?<![\p{L}0-9])

Character Class[\p{L}0-9]

\p{L}any Unicode letter

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Group 1([#＃][·・ー_0-9０-９a-zA-Zａ-ｚＡ-Ｚぁ-んァ-ン一-龠]{1,24})

Character Class[#＃]

#the literal # (35₁₀ / 43₈ / 23₁₆)

＃the literal ＃ (65283₁₀ / 177403₈ / FF03₁₆)

Character Class[·・ー_0-9０-９a-zA-Zａ-ｚＡ-Ｚぁ-んァ-ン一-龠]{1,24}

{1,24}matches between 1 and 24 characters from the set below:

·the literal · (183₁₀ / 267₈ / B7₁₆)

・the literal ・ (12539₁₀ / 30373₈ / 30FB₁₆)

ーthe literal ー (12540₁₀ / 30374₈ / 30FC₁₆)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

０-９one character from ０ (65296₁₀) to ９ (65305₁₀)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

ａ-ｚone character from ａ (65345₁₀) to ｚ (65370₁₀) (case sensitive)

Ａ-Ｚone character from Ａ (65313₁₀) to Ｚ (65338₁₀) (case sensitive)

ぁ-んone character from ぁ (12353₁₀) to ん (12435₁₀)

ァ-ンone character from ァ (12449₁₀) to ン (12531₁₀)

一-龠one character from 一 (19968₁₀) to 龠 (40864₁₀)

Negative Lookahead(?![\p{L}0-9])

Character Class[\p{L}0-9]

\p{L}any Unicode letter

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

u modifier: unicode. Enables Unicode-aware matching and escape syntax

26 tokens

Regular Expression

(?<![\p{L}0-9])([#＃][·・ー_0-9０-９a-zA-Zａ-ｚＡ-Ｚぁ-んァ-ン一-龠]{1,24})(?![\p{L}0-9])

New

Hashtag must be started with # character.
Hashtag will be detected by space character and other special characters (!,@,&,*,%,$).
Example 1: Hello#guys. This is a #test. -> Valid hashtag: #test.
Example 2: Hello#guys. This is a #test!#message. -> Valid hashtag: #test and #message
Example 3: Hello#guys. This is a #test #message. -> Valid hashtag: #test and #message
Example 4: Hello#guys. This is a #test#message. -> Valid hashtag: #test
Example 5: #asdasdasdasdasdasdasdasdasd -> Valid hashtag: none
Example 6: # -> Valid hashtag: none
#日本語#asd => Valid hashtag should be #日本語
#日本語日本語日本語日本語日本語日本語日本語日本語日本語 => Will not a valid hashtag