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 = /(Device\s#\d(\n.*)*?(?=\n\s*Device\s#|\Z))/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(Device\\s#\\d(\\n.*)*?(?=\\n\\s*Device\\s#|\\Z))', 'g') const str = ` Controllers found: 1 ---------------------------------------------------------------------- Physical Device information ---------------------------------------------------------------------- Device #0 Device is a Hard drive State : Online Supported : Yes Transfer Speed : SAS 3.0 Gb/s Reported Channel,Device(T:L) : 0,0(0:0) Reported Location : Enclosure 0, Slot 31 Reported ESD(T:L) : 2,0(0:0) Vendor : HP Model : DG072A4951 Firmware : HPDB Serial number : P2VDJTUA World-wide name : 5000CCA00016CE17 Reserved Size : 109705 KB Used Size : 69900 MB Unused Size : 64 KB Total Size : 70007 MB Write Cache : Enabled (write-back) FRU : None S.M.A.R.T. : No S.M.A.R.T. warnings : 0 Power State : Full rpm Supported Power States : Full rpm,Powered off SSD : No Device #1 Device is a Hard drive State : Online Supported : Yes Transfer Speed : SAS 3.0 Gb/s Reported Channel,Device(T:L) : 0,1(1:0) Reported Location : Enclosure 0, Slot 30 Reported ESD(T:L) : 2,0(0:0) Vendor : HP Model : DG072A4951 Firmware : HPDB Serial number : P2VDLG6A World-wide name : 5000CCA00016E6FB Reserved Size : 109705 KB Used Size : 69900 MB Unused Size : 64 KB Total Size : 70007 MB Write Cache : Enabled (write-back) FRU : None S.M.A.R.T. : No S.M.A.R.T. warnings : 0 Power State : Full rpm Supported Power States : Full rpm,Powered off SSD : No Device #2 Device is a Hard drive State : Online Supported : Yes Transfer Speed : SAS 6.0 Gb/s Reported Channel,Device(T:L) : 0,2(2:0) Reported Location : Enclosure 0, Slot 29 Reported ESD(T:L) : 2,0(0:0) Vendor : HP Model : EG0300FAWHV Firmware : HPDE Serial number : 6SE4RLA90000B206N27S World-wide name : 5000C500429DA878 Reserved Size : 415982 KB Used Size : 285696 MB Unused Size : 64 KB Total Size : 286102 MB Write Cache : Enabled (write-back) FRU : None S.M.A.R.T. : No S.M.A.R.T. warnings : 0 Power State : Full rpm Supported Power States : Full rpm,Powered off SSD : No Device #3 Device is a Hard drive State : Online Supported : Yes Transfer Speed : SAS 6.0 Gb/s Reported Channel,Device(T:L) : 0,3(3:0) Reported Location : Enclosure 0, Slot 28 Reported ESD(T:L) : 2,0(0:0) Vendor : HP Model : EG0300FAWHV Firmware : HPDE Serial number : 6SE4NYMY0000B20416MP World-wide name : 5000C50042999500 Reserved Size : 415982 KB Used Size : 285696 MB Unused Size : 64 KB Total Size : 286102 MB Write Cache : Enabled (write-back) FRU : None S.M.A.R.T. : No S.M.A.R.T. warnings : 0 Power State : Full rpm Supported Power States : Full rpm,Powered off SSD : No`; // 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