Regular Expressions 101

Pro

\ban ASCII word boundary

Positive Lookahead(?=\d{4}\b)

\d{4}a digit, repeated exactly 4 times

\ban ASCII word boundary

8*the literal 8 (56₁₀ / 70₈ / 38₁₆) , repeated any number of times

Non-Capturing Group(?:18*0|08*1)

1st Alternative18*0

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

8*the literal 8 (56₁₀ / 70₈ / 38₁₆) , repeated any number of times

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

2nd Alternative08*1

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

8*the literal 8 (56₁₀ / 70₈ / 38₁₆) , repeated any number of times

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

8*the literal 8 (56₁₀ / 70₈ / 38₁₆) , repeated any number of times

\ban ASCII word boundary

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

\b(?=\d{4}\b)8*(?:18*0|08*1)8*\b

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