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

/
/
gm

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^[\\p{Pd}\\xAD\\x{2212}]+"; final String string = "-s < intorstring >\n" + "-t < string >\n" + "(GTF.featureType)\n" + "Specify the feature type. Only rows which have the matched\n" + "feature type in the provided GTF annotation file will be included for read counting. ‘exon’ by default.\n" + "-T < int >\n" + "(nthreads)\n" + "Number of the threads. The value should be between 1 and\n" + "32. 1 by default.\n" + "-v Output version of the program.\n" + "−−byReadGroup\n" + "(byReadGroup)\n" + "Count reads by read group. Read group information is identified from the header of BAM/SAM input files and the generated count table will include counts for each group in each\n" + "library.\n" + "−−donotsort\n" + "(autosort)\n" + "If specified, paired end reads will not be re-ordered even if\n" + "reads from the same pair were found not to be next to each\n" + "other in the input.\n" + "−−extraAttributes\n" + "< string >\n" + "(GTF.attrType.extra)\n" + "Extract extra attribute types from the provided GTF annotation and include them in the counting output. These attribute\n" + "types will not be used to group features. If more than one attribute type is provided they should be separated by comma\n" + "(in Rsubread featureCounts its value is a character vector).\n" + "−−fraction\n" + "(fraction)\n" + "Assign fractional counts to features. This option must be used\n" + "together with ‘-M’ or ‘-O’ or both. When ‘-M’ is specified,\n" + "each reported alignment from a multi-mapping read (identified via ‘NH’ tag) will carry a count of 1/x, instead of 1 (one),\n" + "where x is the total number of alignments reported for the\n" + "same read. When ‘-O’ is specified, each overlapping feature\n" + "will receive a count of 1/y, where y is the total number of\n" + "features overlapping with the read. When both ‘-M’ and ‘-O’\n" + "are specified, each alignment will carry a count of 1/(x*y)"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html