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

/
/
i

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?i)<img.+src=['"](?P<src>.+?)['"].*>`) var str = `<img class="fr-draggable fr-fil fr-dii" src="//website.com/admin/img/uploads/wysiwyg/ORG_1475303208-troubador1.png" style="width: 300px;" alt="">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla vehicula ligula vitae malesuada mollis. Donec tristique augue ut ipsum lacinia rhoncus. Donec a massa ut urna euismod imperdiet. Integer porta efficitur mollis. Vivamus mollis elementum placerat. Praesent viverra felis sem, at fringilla nulla semper ac. Nunc augue velit, tincidunt sed feugiat quis, dapibus eu est. Duis quis varius quam. Nullam quis ultrices lectus.<img class="fr-draggable fr-fir fr-dii" src="//website.com/admin/img/uploads/wysiwyg/ORG_1475303256-troubador2.png" style="width: 300px;"><strong>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla vehicula ligula vitae malesuada mollis. Donec tristique augue ut ipsum lacinia rhoncus. Donec a massa ut urna euismod imperdiet. Integer porta efficitur mollis. Vivamus mollis elementum placerat. Praesent viverra felis sem, at fringilla nulla semper ac. Nunc augue velit, tincidunt sed feugiat quis, dapibus eu est. Duis quis varius quam. Nullam quis ultrices lectus.</strong>` if len(re.FindStringIndex(str)) > 0 { fmt.Println(re.FindString(str),"found at index",re.FindStringIndex(str)[0]) } }

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/