RegEx

  
^
Start of string
  
*
0 or more
  
+
1 or more
  
?
0 or 1
  
.
Any char but \n 
  
{3}
Exactly 3
  
{3,}
3 or more 
  
{3,5}
3 or 4 or 5
  
{3|5}
3 or 5 
  
[345]
3 or 4 or 5
  
[^34]
not 3 or 4 
  
[a-z]
lowercase a-z
  
[A-Z]
uppercase A-Z 
  
[0-9]
digit 0-9
  
\d
Digit
  
\D
Not digit
  
\w
A-Z,a-z,0-9
  
\W
Not A-Z,a-z,0-9
  
\s
White space (\t\r\n\f)
  
\S
Not (\t\r\n\f)


  
reg[ex]
"rege" or "regx"
  
regex?
"rege" or "regex"
  
regex*
"rege" w/ 0 or more x
  
regex+
"rege" w/ 1 or more x
  
[Rr]egex
Regex" or "regex"
  
\d{3}
Exactly 3 digits
  
\d{3,}
3 or more digits
  
[aeiou] 
Any 1 vowel
  
(0[3-9]|1[0-9]|2[0-5])
Numbers 03-25