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

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /[^\s]\s*END/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('[^\\s]\\s*END', 'g') const str = ` -- if this is a checkbox, IF (@widget = 'Checkbox')BEGIN EXECUTE [dbo].[home_save_slip_checkbox] @school_fk = @school_fk, @slip_fk = @res_output, @definition_field_fk = @definition_field_fk, @notes = '', @points = @points, @student_fk = @student_fk, @academic_year = @academic_year, @occurred_date = @occurred_date END -- if this is an exclusion IF (@widget = 'Exclusion')BEGIN EXECUTE [dbo].[home_save_slip_exclusion] @slip_fk = @res_output, @school_fk = @school_fk, @student_fk = @student_fk , @ocean_user_fk = @ocean_user_fk, @definition_field_fk = @definition_field_fk, @points = @points, @exclusion_type = 'Internal', @exclusion_duration = 3, @start_date = @occurred_date , @notes = '', @d_of_e_reason_code = 'BU' , @reason = '', @academic_year = @academic_year, @category = 'FIXD', @occurred_date = @occurred_date , @definition_location_fk = @definition_location_fk END -- if this is a detention IF (@widget = 'Detention')BEGIN EXECUTE [home_save_slip_detention] @slip_fk = @res_output, @school_fk = @school_fk, @student_fk = @student_fk , @definition_field_fk = @definition_field_fk, @detention_date = @occurred_date , @detention_location_fk = @definition_location_fk, @detention_duration = 30, @points = @points, @definition_slip_fk = @definition_slip_fk, @definition_subject_fk = @definition_subject_fk, @definition_class_fk = -1, @academic_year = @academic_year, @occurred_date = @occurred_date , @detention_reason = '', @detention_work_to_be_completed = '' 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