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

const regex = /{"time": "([^"]+)", "remote_addr": "([^"]+)", "x_forward_for": "([^"]+)", "request_id": "([^"]+)", "remote_user": "([^"]+)", "bytes_sent": (\d+), "request_time": ([\d.]+), "status": (\d+), "vhost": "([^"]+)", "request_proto": "([^"]+)", "path": "([^"]+)", "request_query": "([^"]+)", "request_length": (\d+), "duration": ([\d.]+),"method": "([^"]+)", "http_referrer": "([^"]+)", "http_user_agent": "([^"]+)", "proxy_upstream_name": "([^"]+)", "service_name": "([^"]+)"}/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('{"time": "([^"]+)", "remote_addr": "([^"]+)", "x_forward_for": "([^"]+)", "request_id": "([^"]+)", "remote_user": "([^"]+)", "bytes_sent": (\\d+), "request_time": ([\\d.]+), "status": (\\d+), "vhost": "([^"]+)", "request_proto": "([^"]+)", "path": "([^"]+)", "request_query": "([^"]+)", "request_length": (\\d+), "duration": ([\\d.]+),"method": "([^"]+)", "http_referrer": "([^"]+)", "http_user_agent": "([^"]+)", "proxy_upstream_name": "([^"]+)", "service_name": "([^"]+)"}', 'gm') const str = `{"time": "2023-09-02T13:06:07+00:00", "remote_addr": "127.0.0.6", "x_forward_for": "127.0.0.6", "request_id": "08aaccca-f6e7-4480-9f7b-d157f1dce306", "remote_user": "-", "bytes_sent": 277, "request_time": 0.386, "status": 200, "vhost": "10.160.96.120", "request_proto": "HTTP/1.1", "path": "/savethesale/v1/validateemployee/243060/couponmgmt", "request_query": "-", "request_length": 423, "duration": 0.384,"method": "GET", "http_referrer": "-", "http_user_agent": "PostmanRuntime/7.32.3", "proxy_upstream_name": "ns-sell-save-the-sale-9097", "service_name": "save-the-sale"}`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions