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

Substitution

Processing...

Code Generator

Language

Generated Code

$re = '/,(?=\R|\z)/m'; $str = 'Module Statements,Module,Collection of primitive building blocks and instances of other modules that comprise a network and or instrument. Two types handoff or internal,A redefinition of a module_def shall overwrite a previously defined module_def having the same module_name within the same nameSpace_name.,6.4.5.a), Module Statements,,,A module_def shall have at least one port_def unless it is the top module and contains an AccessLink statement,6.4.5.b), Module Statements,,,"The following objects shall have unique names within a module_def: port_name ? scanRegister_name ? dataRegister_name ? one_hot_scan_group_name ? scanMux_name ? dataMux_name ? clockMux_name ? one_hot_data_group_name ? logicSignal_name ? alias_name",6.4.5.c), Module Statements,,,"The following objects shall have unique names within a module_def: instance_name ? scanInterface_name",6.4.5.d), Module Statements,,,"An inputPort_name shall be one of the following scanInPort_name ? shiftEnPort_name ? captureEnPort_name ? updateEnPort_name ? dataInPort_name ? selectPort_name ? resetPort_name ? tmsPort_name ? tckPort_name ? clockPort_name ? trstPort_name ? addressPort_name ? writeEnPort_name ? readEnPort_name ",6.4.5.e), Module Statements,,,"An outputPort_name shall be one of the following: ? scanOutPort_name ? dataOutPort_name ? toShiftEnPort_name ? toUpdateEnPort_name ? toCaptureEnPort_name ? toSelectPort_name ? toResetPort_name ? toTckPort_name ? toTmsPort_name ? toClockPort_name ? toTrstPort_name ? toIRSelectPort_name",6.4.5.f), Module Statements,,,Multiple inputPort_name port functions that are of type vector_id may share the same SCALAR_ID as long as the indexes form a contiguous range and every index range is of the same either ascending or descending type.,6.4.5.g), Module Statements,,,Multiple outputPort_name port functions that are of type vector_id may share the same SCALAR_ID as long as the indexes form a contiguous range and every index range is of the same either ascending or descending type.,6.4.5.h),'; $subst = ""; $result = preg_replace($re, $subst, $str); echo "The result of the substitution is ".$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 PHP, please visit: http://php.net/manual/en/ref.pcre.php