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 = /(?<=COLLAPSE\sMULTIPLIER\s=\s)(\d*.?\d*)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<=COLLAPSE\\sMULTIPLIER\\s=\\s)(\\d*.?\\d*)', 'gm') const str = ` ========================================================================== STAGE: C/D=1, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 1.918E+00 Converged 2 1 1.944E+00 Converged 3 1 1.945E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1890 No OF EDGES = 2861 No OF NODES = 972 COLLAPSE MULTIPLIER = 1.945 ========================================================================== ========================================================================== STAGE: C/D=2, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 3.505E+00 Converged 2 1 3.613E+00 Converged 3 1 3.594E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1818 No OF EDGES = 2759 No OF NODES = 942 COLLAPSE MULTIPLIER = 3.594 ========================================================================== ========================================================================== STAGE: C/D=3, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 4.493E+00 Converged 2 1 4.632E+00 Converged 3 1 4.648E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1850 No OF EDGES = 2809 No OF NODES = 960 COLLAPSE MULTIPLIER = 4.648 ========================================================================== ========================================================================== STAGE: C/D=4, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 5.111E+00 Converged 2 1 5.368E+00 Converged 3 1 5.361E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1878 No OF EDGES = 2851 No OF NODES = 974 COLLAPSE MULTIPLIER = 5.361 ========================================================================== ========================================================================== STAGE: C/D=5, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 5.768E+00 Converged 2 1 5.903E+00 Converged 3 1 5.898E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1909 No OF EDGES = 2900 No OF NODES = 992 COLLAPSE MULTIPLIER = 5.898 ========================================================================== ========================================================================== STAGE: C/D=6, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 6.088E+00 Converged 2 1 6.312E+00 Converged 3 1 6.360E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1868 No OF EDGES = 2841 No OF NODES = 974 COLLAPSE MULTIPLIER = 6.360 ========================================================================== ========================================================================== STAGE: C/D=7, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 6.309E+00 Converged 2 1 6.671E+00 Converged 3 1 6.727E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1955 No OF EDGES = 2974 No OF NODES = 1020 COLLAPSE MULTIPLIER = 6.727 ========================================================================== ========================================================================== STAGE: C/D=8, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 6.534E+00 Converged 2 1 6.981E+00 Converged 3 1 7.038E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1798 No OF EDGES = 2738 No OF NODES = 941 COLLAPSE MULTIPLIER = 7.038 ========================================================================== ========================================================================== STAGE: C/D=9, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 6.691E+00 Converged 2 1 7.284E+00 Converged 3 1 7.337E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1852 No OF EDGES = 2820 No OF NODES = 969 COLLAPSE MULTIPLIER = 7.337 ========================================================================== ========================================================================== STAGE: C/D=10, Fc, Ø=0, LB ANALYSIS TYPE: Limit Analysis ELEMENT TYPE: Lower TIME SCOPE: Long Term -------------------------------------------------------------------------- ADAPT ITR COLLAPSE SOLVER STATUS STEP MULTIPLIER -------------------------------------------------------------------------- 1 1 6.900E+00 Converged 2 1 7.506E+00 Converged 3 1 7.584E+00 Converged -------------------------------------------------------------------------- No OF TRIANGLES = 1868 No OF EDGES = 2843 No OF NODES = 976 COLLAPSE MULTIPLIER = 7.584 ==========================================================================`; // 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