Regular Expressions 101

Explanation

Pro

\Astart of string

Atomic Group(?> #MAIN iteration (atomic only for efficiency) (?<upper>[A-Z]) # an uppercase letter | # or (?<lower>[a-z]) # a lowercase letter | # or (?<digit>[0-9]) # a digit | # or . # anything else ){8,}?

{8,}?repeats the group contents below at least 8 times:

1st Alternative #MAIN iteration (atomic only for efficiency) (?<upper>[A-Z]) # an uppercase letter

Comment: MAIN iteration (atomic only for efficiency)

Group upper(?<upper>[A-Z])

Character Class[A-Z]

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

Comment: an uppercase letter

2nd Alternative # or (?<lower>[a-z]) # a lowercase letter

Comment: or

Group lower(?<lower>[a-z])

Character Class[a-z]

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

Comment: a lowercase letter

3rd Alternative # or (?<digit>[0-9]) # a digit

Comment: or

Group digit(?<digit>[0-9])

Character Class[0-9]

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

Comment: a digit

4th Alternative # or . # anything else

Comment: or

.any character (except for line terminators)

Comment: anything else

Comment: REPEATED 8+ times

Comment:

Comment: CONDITIONS:

Condition(?(upper) # 1. There must be at least 1 uppercase (?(lower) # 2. If (1), there must be 1 lowercase (?(digit) # 3. If (2), there must be 1 digit | (?!) # Else fail ) # | (?!) # Else fail ) # | (?!) # Else fail )

Uses the first branch if group upper matched

If the condition is true, match this branch: # 1. There must be at least 1 uppercase (?(lower) # 2. If (1), there must be 1 lowercase (?(digit) # 3. If (2), there must be 1 digit | (?!) # Else fail ) # | (?!) # Else fail ) #

Comment: 1. There must be at least 1 uppercase

Condition(?(lower) # 2. If (1), there must be 1 lowercase (?(digit) # 3. If (2), there must be 1 digit | (?!) # Else fail ) # | (?!) # Else fail )

Uses the first branch if group lower matched

If the condition is true, match this branch: # 2. If (1), there must be 1 lowercase (?(digit) # 3. If (2), there must be 1 digit | (?!) # Else fail ) #

Comment: 2. If (1), there must be 1 lowercase

Condition(?(digit) # 3. If (2), there must be 1 digit | (?!) # Else fail )

Uses the first branch if group digit matched

If the condition is true, match this branch: # 3. If (2), there must be 1 digit

Comment: 3. If (2), there must be 1 digit

Otherwise, match this branch: (?!) # Else fail

Negative Lookahead(?!) — always fails to match

Comment: Else fail

Comment:

Otherwise, match this branch: (?!) # Else fail

Negative Lookahead(?!) — always fails to match

Comment: Else fail

Comment:

Otherwise, match this branch: (?!) # Else fail

Negative Lookahead(?!) — always fails to match

Comment: Else fail

Comment:

Global pattern flags

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

\A
(?>                       #MAIN iteration (atomic only for efficiency)
    (?<upper>[A-Z])       #  an uppercase letter
  |                       # or
    (?<lower>[a-z])       #  a lowercase letter
  |                       # or
    (?<digit>[0-9])       #  a digit
  |                       # or
    .                     #  anything else
){8,}?                    #REPEATED 8+ times
                          #
                          #CONDITIONS:
(?(upper)                 # 1. There must be at least 1 uppercase
    (?(lower)             #    2. If (1), there must be 1 lowercase
        (?(digit)         #       3. If (2), there must be 1 digit
          | (?!)          #          Else fail
        )                 #
      | (?!)              #       Else fail
    )                     #
  | (?!)                  #    Else fail
)                         #

New

1Bc45678

Substitution

1Bc45678