Regular Expressions 101

Pro

^start of string

--start the literal text --start↵ (case sensitive)

Group 1(1?[\-\.\_]?)

1?optionally matches the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[\-\.\_]?

?matches at most one character from the set below:

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\_the literal _ (95₁₀ / 137₈ / 5F₁₆)

question mark makes the block or single character before it optional the literal text question mark makes the block or single character before it optional↵ (case sensitive)

Group 2([0-9]{3})

Character Class[0-9]{3}

{3}matches exactly 3 characters from the set below:

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

the literal ↵ (10₁₀ / 12₈ / A₁₆)

Group 3(-?)

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

the literal ↵ (10₁₀ / 12₈ / A₁₆)

Group 4([0-9]{4})

Character Class[0-9]{4}

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

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

the literal ↵ (10₁₀ / 12₈ / A₁₆)

$end of string, or before its final line terminator

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

^ --start
(1?[\-\.\_]?) question mark makes the block or single character before it optional
([0-9]{3})
(-?)
([0-9]{4})
$

Substitution