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

r"
"
g

Test String

Code Generator

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`\d{1,2}\/optimized\/.+\.tif`) var str = `{ $b$1/optimized/8757901_fpx.tif }&cropN=0, 0, 14, 1&anchor=0, 0&layer=1&size=23, 23&src=is{ $b$2/optimized/8757902_fpx.tif }&anchor=0, 0&posN=0.071, 0&layer=2&size=23, 23&src=is{ $b$4/optimized/8234544_fpx.tif }&anchor=0, 0&posN=0.143, 0&layer=3&size=23, 23&src=is{ $b$7/optimized/1111977_fpx.tif }&anchor=0, 0&posN=0.214, 0&layer=4&size=23, 23&src=is{ $b$0/optimized/8538460_fpx.tif }&anchor=0, 0&posN=0.286, 0&layer=5&size=23, 23&src=is{ $b$5/optimized/8234545_fpx.tif }&anchor=0, 0&posN=0.357, 0&layer=6&size=23, 23&src=is{ $b$3/optimized/1111973_fpx.tif }&anchor=0, 0&posN=0.429, 0&layer=7&size=23, 23&src=is{ $b$7/optimized/1252857_fpx.tif }&anchor=0, 0&posN=0.5, 0&layer=8&size=23, 23&src=is{ $b$8/optimized/1252858_fpx.tif }&anchor=0, 0&posN=0.571, 0&layer=9&size=23, 23&src=is{ $b$7/optimized/8234547_fpx.tif }&anchor=0, 0&posN=0.643, 0&layer=10&size=23, 23&src=is{ $b$0/optimized/8757900_fpx.tif }&anchor=0, 0&posN=0.714, 0&layer=11&size=23, 23&src=is{ $b$0/optimized/1111970_fpx.tif }&anchor=0, 0&posN=0.786, 0&layer=12&size=23, 23&src=is{ $b$1/optimized/1111971_fpx.tif }&anchor=0, 0&posN=0.857, 0&layer=13&size=23, 23&src=is{ $b$2/optimized/1111972_fpx.tif }&anchor=0, 0&posN=0.929, 0&layer=14&op_sharpen=1&fmt=jpeg&qlt=90, 0&hei=23') 322px 0 transparent;` 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/