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"
"
gm

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('(?:ALARM[\\s]*)(?:\\d*)[A-Za-z\\s\\d\\.=]*(?:Alarm\\sraised\\stime)\\s+=\\s+([\\d\\-]+\\s[\\d\\:]+)\\s+(?:Location\\sinfo)\\s+=\\s+Local\\sCell\\sID=([\\d]+)(?:,\\s[a-zA-Z]+\\s[A-Z]+\\s[A-Z]+\\s[a-zA-Z\\=,]+\\s[a-zA-Z\\=-]+\\s[a-zA-Z\\=-]+\\s[a-zA-Z\\=-_,]+)[\\s\\,A-Za-z0-9=\\_]*(?:eNodeB\\sID=)([0-9]+)(?:,.+\\s\\s+.+\\s+)(?:Cleared\\stype)\\s+=\\s+([a-zA-Z ]+)(?:[\\sA-Za-z\\s=]*)([\\d-]*\\s[\\d:]+)', 'gm') const str = `L_SAMBIL +++ L_SAMBIL 2020-09-21 11:53:53 O&M #1502 %%/*1882154167*/LST ALMLOG:ALMTP=all,CLRFLG=cleared-1&uncleared-1,CLRSD=2020&09&21,CLRED=2020&09&22,STARTAID=29240,ENDAID=29240;%% RETCODE = 0 Operation succeeded ALARM 72712 Fault Major eNodeB 29240 Signaling Sync serial No. = 162656 Alarm name = Cell Unavailable Alarm raised time = 2020-09-21 06:36:19 Location info = Local Cell ID=2, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL2, eNodeB ID=15080, Cell ID=2, Specific Problem=External link fault Function = eNodeB Function Name=L_SAMBIL, objId=0 Cleared type = Normally cleared Cleared time = 2020-09-21 06:39:42 Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL Special info1 = AF_L=L_SAMBIL ALARM 72713 Fault Major eNodeB 29240 Signaling Sync serial No. = 162655 Alarm name = Cell Unavailable Alarm raised time = 2020-09-21 06:36:19 Location info = Local Cell ID=3, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL3, eNodeB ID=15080, Cell ID=3, Specific Problem=External link fault Function = eNodeB Function Name=L_SAMBIL, objId=0 Cleared type = Normally cleared Cleared time = 2020-09-21 06:39:41 Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL Special info1 = AF_L=L_SAMBIL ALARM 72711 Fault Major eNodeB 29240 Signaling Sync serial No. = 162654 Alarm name = Cell Unavailable Alarm raised time = 2020-09-21 06:36:19 Location info = Local Cell ID=1, Cell FDD TDD indication=FDD, NB-IoT Cell Flag=FALSE, Cell Name=L_SAMBIL1, eNodeB ID=15080, Cell ID=1, Specific Problem=External link fault Function = eNodeB Function Name=L_SAMBIL, objId=0 Cleared type = Normally cleared Cleared time = 2020-09-21 06:39:41 Special info = RAT_INFO=L, AFFECTED_RAT=L, DID=NULL Special info1 = AF_L=L_SAMBIL (Number of results = 3) --- END`; // 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