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

/
/
gm

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^\\w++\\W++((?<=\\\")[\\w-]+(?=\"))\\W+((?<=\\\")[\\w-]+(?=\"))[\\S\\s]+?(count\\W+=.*)[\\S\\s]+?^\\}$"; final String string = "resource \"aws_iam_role\" \"my_test_payer_specific_role\" {\n" + " count = \"${(var.payer_account == \"380834257621\")?1:0}\"\n\n" + " name = \"my_test_payer_specific_role\"\n" + " max_session_duration = \"7200\"\n" + " assume_role_policy = \"${data.aws_iam_policy_document.my_test_payer_specific_role-policy.json}\"\n" + " tags = \"${var.resources_tags}\"\n" + " lifecycle {\n" + " ignore_changes = [\n" + " \"permissions_boundary\"\n" + " ]\n" + " }\n" + "}\n\n" + "resource \"aws_iam_role_policy_attachment\" \"my_test_payer_specific_role-policy-attachment\" {\n" + " role = \"${aws_iam_role.my_test_payer_specific_role.name}\"\n" + " count = \"${(var.payer_account == \"380834257621\")?1:0}\"\n" + " policy_arn = \"arn:${var.partition}:iam::aws:policy/AdministratorAccess\"\n" + "}\n\n" + "data \"aws_iam_policy_document\" \"my_test_payer_specific_role-policy\" {\n" + " count = \"${(var.payer_account == \"380834257621\")?1:0}\"\n" + " statement {\n" + " actions = [\"sts:AssumeRole\"]\n\n" + " principals {\n" + " type = \"AWS\"\n" + " identifiers = [\"arn:${var.partition}:iam::${var.payer_account}:root\", \"arn:${var.partition}:iam::380834257621:root\"]\n" + " }\n" + " }\n" + "}"; 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