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 = "\\\"event_sub_type\\\":\\\"((WAN\\s+Firewall)|TLS)"; final String string = "1. event_sub_type\":\"WAN\n\n" + " \n\n" + "{\"event_count\":1,\"ISP_name\":\"Shanghai internet\",\"rule\":\"Initial Connectivity Rule\",\"dest_is_site_or_vpn\":\"Site\",\"src_isp_ip\":\"0.0.0.0\",\"time_str\":\"2023-11-28T04:27:40Z\",\"src_site\":\"CHINA-AZURE-E2\",\"src_ip\":\"0.0.0.1\",\"internalId\":\"54464646\",\"dest_site_name\":\"china_112,\"event_type\":\"Security\",\"src_country_code\":\"CN\",\"action\":\"Monitor\",\"subnet_name\":\"cn-001.net-vnet-1\",\"pop_name\":\"Shanghai_1\",\"dest_port\":443,\"dest_site\":\"china_connect\",\"rule_name\":\"Initial Connectivity Rule\",\"event_sub_type\":\"WAN Firewall\",\"insertionDate\":1701188916690,\"ip_protocol\":\"TCP\",\"rule_id\":\"101238\",\"src_is_site_or_vpn\":\"Site\",\"account_id\":5555,\"application\":\"HTTP(S)\",\"src_site_name\":\"china_connect\",\"src_country\":\"China\",\"dest_ip\":\"0.0.0.0\",\"os_type\":\"OS_ANDROID\",\"app_stack\"\"TCP\",\"TLS\",\"HTTP(S)\"],\"time\":1701188860834}\n\n" + " \n\n" + "2. \"event_sub_type\":\"TLS\",\"\n\n" + " \n\n" + "{\"event_count\":4,\"http_host_name\":\"isp.vpn\",\"ISP_name\":\"China_internet\",\"src_isp_ip\":\"0.0.0.0\",\"tls_version\":\"TLSv1.3\",\"time_str\":\"2023-11-28T04:27:16Z\",\"src_site\":\"china_mtt\",\"src_ip\":\"0.0.0.0\",\"internalId\":\"rtrgrtr\",\"domain_name\":\"china.gh.com\",\"event_type\":\"Security\",\"src_country_code\":\"CN\",\"tls_error_description\":\"unknown CA\",\"action\":\"Alert\",\"subnet_name\":\"0.0.0.0/24\",\"pop_name\":\"china_1\",\"dest_port\":443,\"event_sub_type\":\"TLS\",\"insertionDate\":1701188915580,\"dest_country_code\":\"SG\",\"tls_error_type\":\"fatal\",\"dns_name\":\"china.com\",\"traffic_direction\":\"OUTBOUND\",\"src_is_site_or_vpn\":\"Site\",\"account_id\":56565,\"application\":\"Netskope\",\"src_site_name\":\"CHINA-44\",\"src_country\":\"China\",\"dest_ip\":\"0.0.0.0\",\"os_type\":\"OS_WINDOWS\",\"time\":1701188836011,\"dest_country\":\"Singapore\"}"; 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