Regular Expressions 101

Pro

^start of line

Character Class[01]{2}

{2}matches exactly 2 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Positive Lookahead(?=[01]{8}$)

Character Class[01]{8}

{8}matches exactly 8 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

$end of line

Group 1([01]{0,2}1[01]{0,2}1[01]{0,2})

Character Class[01]{0,2}

{0,2}matches between 0 and 2 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[01]{0,2}

{0,2}matches between 0 and 2 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[01]{0,2}

{0,2}matches between 0 and 2 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[01]{4}

{4}matches exactly 4 characters from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

$end of line

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

^[01]{2}(?=[01]{8}$)([01]{0,2}1[01]{0,2}1[01]{0,2})[01]{4}$

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