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 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]
  • 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
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)out of|of|\/)[\s]?(?P<core2>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?)`) var str = `ajnxaslndsa;ndaJDASDNsadnKDNadk;NADK'nadkAnaskdmaskdnajfbajfnakdnaj;knasjnakdna;jkdna;nda;dna;kdnas;dkns so as sadasldka aldaskl . asdas asd 5,400 cgy 40.00 cgy 4 cgy gleason score 6/10(4+3), = 7 ) 1.1- 0.6,df 2,4-3,6 asdf 4+5+6 gleason's pattern: 2+3, 5 gleason score = 5(2+3) score 1+2, (score 7) gleason Dec 2011-23 jan 500,000.012 cgy sdfsfsodm sdfsd f sdfsd afdas. s adasas dasd as asdasdaskd askdm askdmas'ljdnas;das.ndaskjndajkndWJDNAksz (?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)out of|of|\/)[\s]?(?P<core2>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?) (?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)core[s]? out of)[\s]?(?P<core2>(?i)[A-Z0-9]+) (?:(?i)involving)[\s]?(?P<core1>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?) 1 of 3 core one of three cores involving 1/2 cores involving five of six cores two of the cores one of multiple cores 1 of multiple cores two of 4 cores 5 of six cores (1/8 needle cores) (3/7 cores) one out of six cores two cores out of two 1 core out of 2 involving 1 core involving two cores gleason score 9, 4+5=9/10, PSA = 27.60, 8 specimens {0,1SDf00} 10% 20% (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\-]*\s*\K(\d)\s*\-\s*(\d)(?=\D\-) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\,\#]*\s*\K(\d)\s*\,\s*(\d)(?=\D) [\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) [\w\s\p{P}\=]*[^0-9\.\-]*\s*\K(\d)\s*\+\s*(\d)(?=\D\-) (?<=[\\s])\\s*|^\\s+|\\s+$ ` 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/