Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A single character of: a, b, c or d
    [[ab][cd]]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Character class intersection
    [\w&&[^\d]]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)^(?<name>([!@#$?]*)([A-Za-z0-9]+))+([!@#$?]+)=(?<length>\d+)<<.*$`) var str = `Examples for valid input: !Ma$$ka!lu!@=9<<ghtucjdhs !@Eve?#rest!#=7<<vbnfhfg Examples of invalid input: anna@fg<<jhsd@bx!=4 #n...s!n-<<tyuhgf4 Nan$ga!Parbat=8<<gh2tn !@Ma?na?sl!u@=7<<tv58ycb4845 E!ve?rest=.6<<tuvz26 !K@2.,##$=4<<tvnd !Shiha@pan@gma##9<<tgfgegu67 !###Anna@pur@na##=16<<tv5dekdz8x11ddkc Ka?!#nch@@en@ju##nga@=3<<thfbghvn =9Cho?@#Oyu<<thvb7ydht Nan??ga#Par!ba!t?=16<<twm03q2rx5hpmyr6 Dhau??la#gi@ri?!#=3<<bvnfhrtiuy Last note ` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/