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

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = new RegExp('([\\w_\\.]+)=([\\-\\w_\\.]+);', 'gm') const str = `g_MA1=17; g_MA2=20; ExtTimeWindowStart=7; ExtTimeWindowDuration=14; ExtDayNotToTrade=6; g_FilterState=0; g_MAType=3; g_use_MA_Factor=0; g_MA_LB_Factor=2; g_activateMA3=0; g_MA3=80; g_activateBBKC=0; g_BBKCHighVolatility=0; g_BBKC=10; g_BBKCThreshold=0.75; g_BBKCBarsLength=1; g_activateSNR=1; g_SNRCycle=0; g_SNRPeriod=25; g_SNRLevel=-15; g_SNRBarsLength=1; g_activateTI=1; g_TI_LB=20; g_MA1_Weight=3; g_MA2_Weight=2; g_MA3_Weight=1; g_MA_TypeTI=3; g_IsNormalized=1; g_UpperThreshold=30; g_LowerThreshold=-30; g_orderType=0; g_inversionSwitch=1; g_barsNumber=3; g_averageFactor=0; g_DayLength=1; g_activateOpposite=1; g_activateDayTrade=0; g_activateTradeDuration=0; g_tradeDurationBars=10; ExtSlPercent=0.25;`; const subst = `\1=\2\n\1,F=0\n\1,1=0\n\1,2=0\n\1,3=0`; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log('Substitution result: ', result);

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