RegEx for Javascript to allow only alphanumeric

Question

I need to find a reg ex that only allows alphanumeric  So far  everyone I try only works if the string is alphanumeric  meaning contains both a letter and a number  I just want one what would allow either and not require both

User · Accepted Answer

a-z0-9    i            Start of string  a-z0-9   a or b or c or     z or 0 or 1 or     9           one or more times  change to   to allow empty string            end of string      i        case-insensitive  Update  supporting universal characters  if you need to this regexp supports universal character you can find list of unicode characters here  for example      a-zA-Z0-9 u0600- u06FF u0660- u0669 u06F0- u06F9   -      this will support persian

User · Answer

I have string similar to Samsung Galaxy A10s 6 2-Inch  2GB 32GB ROM  Android 9 0   13MP 2MP   8MP Dual SIM 4000mAh 4G LTE Smartphone - Black  BF19   Below is what i did   string replace    a-zA-Z0-9    -  g      split      join  -   split      join  -   toLowerCase     Notice i allowed    - then use split   and join   to replace   to - and space to - respectively   I ended up getting something like this  samsung-galaxy-a10s-6 2-inch-2gb-32gb-rom-android-9 0-13mp-2mp-8mp-dual-sim-4000mah-4g-lte-smartphone-black-bf19-20 which is what i wanted   There might be a better solution but this is what i found working fine for me

User · Answer

s   0-9a-zA-Z    s     or  if you want a minimum of one character     s   0-9a-zA-Z    s     Square brackets indicate a set of characters     is start of input     is end of input  or newline  depending on your options     s is whitespace   The whitespace before and after is optional   The parentheses are the grouping operator to allow you to extract the information you want   EDIT  removed my erroneous use of the  w character set

User · Answer

It seems like many users have noticed this these regular expressions will almost certainly fail unless we are strictly working in English  But I think there is an easy way forward that would not be so limited    make a copy of your string in all UPPERCASE make a second copy in all lowercase   Any characters that match in those strings are definitely not alphabetic in nature   let copy1   originalString toUpperCase    let copy2   originalString toLowerCase    for let i 0  i lt originalString length  i          let bIsAlphabetic    copy1 i     copy2 i        Optionally  you can also detect numerics by just looking for digits 0 to 9

User · Answer

A little bit late  but this worked for me     a-z A-Z 0-9   g  a-z   anything from a to z  A-Z   anything from A to Z  upper case   0-9   any number from 0 to 9  It will allow anything inside square brackets  so let s say you want to allow any other character  for example    quot   quot  and  quot   quot   the regex would be something like this     a-z A-Z 0-9       g  This site will help you to test your regex before coding  https   regex101 com  Feel free to modify and add anything you want into the brackets  Regards

User · Answer

Instead of checking for a valid alphanumeric string  you can achieve this indirectly by checking the string for any invalid characters  Do so by checking for anything that matches the complement of the valid alphanumeric string      a-z d  i       Here is an example   var alphanumeric    someStringHere   var myRegEx       a-z d  i  var isValid     myRegEx test alphanumeric      Notice the logical not operator at isValid  since I m testing whether the string is false  not whether it s valid

User · Answer

Alphanumeric with case sensitive  if     a-zA-Z0-9     test  quot SoS007 quot        alert  quot match quot

User · Answer

Try this    Replace you field ID with  name    a-z a to z   A-Z A to Z   0-9 0 to 9   jQuery document  ready function             name   keypress function  e            var regex   new RegExp    a-zA-Z0-9 s               var str   String fromCharCode  e charCode   e which   e charCode           if  regex test str                 return true                    e preventDefault            return false

User · Answer

A little bit late  but this worked for me     a-z A-Z 0-9   g  a-z   anything from a to z  A-Z   anything from A to Z  upper case   0-9   any number from 0 to 9  It will allow anything inside square brackets  so let s say you want to allow any other character  for example    quot   quot  and  quot   quot   the regex would be something like this     a-z A-Z 0-9       g  This site will help you to test your regex before coding  https   regex101 com  Feel free to modify and add anything you want into the brackets  Regards

User · Answer

Extend the string prototype to use throughout your project      String prototype alphaNumeric   function             return this replace    a-z0-9  gi              Usage        I don t know what to say   alphaNumeric          Idontknowwhattosay

User · Answer

Use the word character class  The following is equivalent to a   a-zA-Z0-9         w     Explanation      start of string  w any word character  A-Z  a-z  0-9        end of string   Use     w    g if you don t want to match the underscore

User · Answer

Jquery to accept only NUMBERS  ALPHABETS and SPECIAL CHARECTERS  x000D   x000D   lt html gt  x000D   lt head gt  x000D   lt script src  https   cdnjs cloudflare com ajax libs jquery 3 3 1 jquery min js  gt  lt  script gt  x000D   lt  head gt  x000D   x000D   lt body gt  x000D  Enter Only Numbers   x000D   lt input type  text  id  onlynumbers  gt  x000D   lt br gt  lt br gt  x000D  Enter Only Alphabets   x000D   lt input type  text  id  onlyalpha  gt  x000D   lt br gt  lt br gt  x000D  Enter other than Alphabets and numbers like special characters   x000D   lt input type  text  id  speclchar  gt  x000D   x000D   lt script gt  x000D          onlynumbers   keypress function e    x000D        var letters    0-9  g    g means global x000D        if   e key  match letters   e preventDefault    x000D       x000D       x000D          onlyalpha   keypress function e    x000D        var letters    a-z  gi    i means ignorecase x000D        if   e key  match letters   e preventDefault    x000D       x000D       x000D          speclchar   keypress function e    x000D        var letters    0-9a-z  gi   x000D        if  e key  match letters   e preventDefault    x000D       x000D       lt  script gt  x000D   lt  body gt  x000D   lt  html gt  x000D   x000D   x000D      JQUERY to accept only NUMBERS   ALPHABETS and SPECIAL CHARACTERS       lt  DOCTYPE html gt          onlynumbers   keypress function e          var letters    0-9  g    g means global       if   e key  match letters   e preventDefault                     onlyalpha   keypress function e          var letters    a-z  gi    i means ignorecase       if   e key  match letters   e preventDefault                     speclchar   keypress function e          var letters    0-9a-z  gi         if  e key  match letters   e preventDefault                  lt html gt   lt head gt   lt script src  https   ajax googleapis com ajax libs jquery 3 4 1 jquery min js  gt               Enter Only Numbers                 Enter Only Alphabets                 Enter other than Alphabets and numbers like special characters          lt  body gt   lt  html gt

User · Answer

Alphanumeric with case sensitive  if     a-zA-Z0-9     test  quot SoS007 quot        alert  quot match quot

User · Answer

Use the word character class  The following is equivalent to a   a-zA-Z0-9         w     Explanation      start of string  w any word character  A-Z  a-z  0-9        end of string   Use     w    g if you don t want to match the underscore

User · Answer

I have string similar to Samsung Galaxy A10s 6 2-Inch  2GB 32GB ROM  Android 9 0   13MP 2MP   8MP Dual SIM 4000mAh 4G LTE Smartphone - Black  BF19   Below is what i did   string replace    a-zA-Z0-9    -  g      split      join  -   split      join  -   toLowerCase     Notice i allowed    - then use split   and join   to replace   to - and space to - respectively   I ended up getting something like this  samsung-galaxy-a10s-6 2-inch-2gb-32gb-rom-android-9 0-13mp-2mp-8mp-dual-sim-4000mah-4g-lte-smartphone-black-bf19-20 which is what i wanted   There might be a better solution but this is what i found working fine for me

User · Answer

s   0-9a-zA-Z    s     or  if you want a minimum of one character     s   0-9a-zA-Z    s     Square brackets indicate a set of characters     is start of input     is end of input  or newline  depending on your options     s is whitespace   The whitespace before and after is optional   The parentheses are the grouping operator to allow you to extract the information you want   EDIT  removed my erroneous use of the  w character set

User · Answer

Input these code to your SCRATCHPAD and see the action   var str String  Blah-Blah1 2 oo0 01 amp zz kick   replace     w-  ig

User · Answer

Even better than Gayan Dissanayake pointed out      - w s       Now   a-zA-Z0-9    can be represented as   w       You may want to use  s instead of space  Note that  s takes care of whitespace and not only one space character

User · Answer

This will work          a-zA-Z        0-9   a-zA-Z0-9      It accept only alphanumeriuc characters alone  test cases pased    dGgs1s23 - valid 12fUgdf  - valid  121232   - invalid   abchfe   - invalid   abd     - invalid   42232 5  - invalid   or     You can also try this one  this expression satisfied at least one number and one character and no other special characters         0-9        a-zA-Z    a-zA-Z0-9       in angular can test like    scope str    12fUgdf   var pattern   new RegExp         0-9        a-zA-Z    a-zA-Z0-9         scope testResult   pattern test  scope str     PLUNKER DEMO  Refered Regular expression for alphanumeric in Angularjs

User · Answer

Even better than Gayan Dissanayake pointed out      - w s       Now   a-zA-Z0-9    can be represented as   w       You may want to use  s instead of space  Note that  s takes care of whitespace and not only one space character

User · Answer

JAVASCRIPT to accept only NUMBERS  ALPHABETS and SPECIAL CHARECTERS   x000D   x000D  document getElementById  onlynumbers   onkeypress   function  e    x000D   onlyNumbers e key  e  x000D     x000D   x000D  document getElementById  onlyalpha   onkeypress   function  e    x000D   onlyAlpha e key  e  x000D     x000D   x000D  document getElementById  speclchar   onkeypress   function  e    x000D   speclChar e key  e  x000D     x000D   x000D  function onlyNumbers key  e    x000D   var letters      0-9  g    g means global x000D   if    key  match letters   e preventDefault    x000D    x000D   x000D  function onlyAlpha key  e    x000D   var letters      a-z  gi    i means ignorecase x000D   if    key  match letters   e preventDefault    x000D    x000D   x000D  function speclChar key  e    x000D   var letters      0-9a-z  gi  x000D   if   key  match letters   e preventDefault    x000D    x000D   lt html gt  x000D      lt head gt  lt  head gt  x000D      lt body gt  x000D        Enter Only Numbers   x000D         lt input id  onlynumbers  type  text  gt  x000D         lt br gt  lt br gt  x000D        Enter Only Alphabets   x000D         lt input id  onlyalpha  type  text   gt  x000D         lt br gt  lt br gt  x000D        Enter other than Alphabets and numbers like special characters   x000D         lt input id  speclchar  type  text   gt  x000D      lt  body gt  x000D   lt  html gt  x000D   x000D   x000D

User · Answer

Jquery to accept only NUMBERS  ALPHABETS and SPECIAL CHARECTERS  x000D   x000D   lt html gt  x000D   lt head gt  x000D   lt script src  https   cdnjs cloudflare com ajax libs jquery 3 3 1 jquery min js  gt  lt  script gt  x000D   lt  head gt  x000D   x000D   lt body gt  x000D  Enter Only Numbers   x000D   lt input type  text  id  onlynumbers  gt  x000D   lt br gt  lt br gt  x000D  Enter Only Alphabets   x000D   lt input type  text  id  onlyalpha  gt  x000D   lt br gt  lt br gt  x000D  Enter other than Alphabets and numbers like special characters   x000D   lt input type  text  id  speclchar  gt  x000D   x000D   lt script gt  x000D          onlynumbers   keypress function e    x000D        var letters    0-9  g    g means global x000D        if   e key  match letters   e preventDefault    x000D       x000D       x000D          onlyalpha   keypress function e    x000D        var letters    a-z  gi    i means ignorecase x000D        if   e key  match letters   e preventDefault    x000D       x000D       x000D          speclchar   keypress function e    x000D        var letters    0-9a-z  gi   x000D        if  e key  match letters   e preventDefault    x000D       x000D       lt  script gt  x000D   lt  body gt  x000D   lt  html gt  x000D   x000D   x000D      JQUERY to accept only NUMBERS   ALPHABETS and SPECIAL CHARACTERS       lt  DOCTYPE html gt          onlynumbers   keypress function e          var letters    0-9  g    g means global       if   e key  match letters   e preventDefault                     onlyalpha   keypress function e          var letters    a-z  gi    i means ignorecase       if   e key  match letters   e preventDefault                     speclchar   keypress function e          var letters    0-9a-z  gi         if  e key  match letters   e preventDefault                  lt html gt   lt head gt   lt script src  https   ajax googleapis com ajax libs jquery 3 4 1 jquery min js  gt               Enter Only Numbers                 Enter Only Alphabets                 Enter other than Alphabets and numbers like special characters          lt  body gt   lt  html gt

User · Answer

If you wanted to return a replaced result  then this would work   var a    Test123    TEST   var b   a replace    a-z0-9  gi      console log b     This would return   Test123TEST   Note that the gi is necessary because it means global  not just on the first match   and case-insensitive  which is why I have a-z instead of a-zA-Z  And the   inside the brackets means  anything not in these brackets    WARNING  Alphanumeric is great if that s exactly what you want  But if you re using this in an international market on like a person s name or geographical area  then you need to account for unicode characters  which this won t do  For instance  if you have a name like    lvar     it would make it  lvar

User · Answer

This will work          a-zA-Z        0-9   a-zA-Z0-9      It accept only alphanumeriuc characters alone  test cases pased    dGgs1s23 - valid 12fUgdf  - valid  121232   - invalid   abchfe   - invalid   abd     - invalid   42232 5  - invalid   or     You can also try this one  this expression satisfied at least one number and one character and no other special characters         0-9        a-zA-Z    a-zA-Z0-9       in angular can test like    scope str    12fUgdf   var pattern   new RegExp         0-9        a-zA-Z    a-zA-Z0-9         scope testResult   pattern test  scope str     PLUNKER DEMO  Refered Regular expression for alphanumeric in Angularjs

User · Answer

Try this    Replace you field ID with  name    a-z a to z   A-Z A to Z   0-9 0 to 9   jQuery document  ready function             name   keypress function  e            var regex   new RegExp    a-zA-Z0-9 s               var str   String fromCharCode  e charCode   e which   e charCode           if  regex test str                 return true                    e preventDefault            return false

User · Answer

Extend the string prototype to use throughout your project      String prototype alphaNumeric   function             return this replace    a-z0-9  gi              Usage        I don t know what to say   alphaNumeric          Idontknowwhattosay

User · Answer

Save this constant  const letters      a-zA-Z0-9       now  for checking part use  match    const string    Hey there        get string from a keyup listner let id         iterate through each letters for  var i   0  i  lt  string length  i        if  string i  match letters          id    string i      else          In case you want to replace with something else     id     -          return id

User · Answer

Input these code to your SCRATCHPAD and see the action   var str String  Blah-Blah1 2 oo0 01 amp zz kick   replace     w-  ig

User · Answer

JAVASCRIPT to accept only NUMBERS  ALPHABETS and SPECIAL CHARECTERS   x000D   x000D  document getElementById  onlynumbers   onkeypress   function  e    x000D   onlyNumbers e key  e  x000D     x000D   x000D  document getElementById  onlyalpha   onkeypress   function  e    x000D   onlyAlpha e key  e  x000D     x000D   x000D  document getElementById  speclchar   onkeypress   function  e    x000D   speclChar e key  e  x000D     x000D   x000D  function onlyNumbers key  e    x000D   var letters      0-9  g    g means global x000D   if    key  match letters   e preventDefault    x000D    x000D   x000D  function onlyAlpha key  e    x000D   var letters      a-z  gi    i means ignorecase x000D   if    key  match letters   e preventDefault    x000D    x000D   x000D  function speclChar key  e    x000D   var letters      0-9a-z  gi  x000D   if   key  match letters   e preventDefault    x000D    x000D   lt html gt  x000D      lt head gt  lt  head gt  x000D      lt body gt  x000D        Enter Only Numbers   x000D         lt input id  onlynumbers  type  text  gt  x000D         lt br gt  lt br gt  x000D        Enter Only Alphabets   x000D         lt input id  onlyalpha  type  text   gt  x000D         lt br gt  lt br gt  x000D        Enter other than Alphabets and numbers like special characters   x000D         lt input id  speclchar  type  text   gt  x000D      lt  body gt  x000D   lt  html gt  x000D   x000D   x000D

User · Answer

If you wanted to return a replaced result  then this would work   var a    Test123    TEST   var b   a replace    a-z0-9  gi      console log b     This would return   Test123TEST   Note that the gi is necessary because it means global  not just on the first match   and case-insensitive  which is why I have a-z instead of a-zA-Z  And the   inside the brackets means  anything not in these brackets    WARNING  Alphanumeric is great if that s exactly what you want  But if you re using this in an international market on like a person s name or geographical area  then you need to account for unicode characters  which this won t do  For instance  if you have a name like    lvar     it would make it  lvar

User · Answer

s   0-9a-zA-Z    s     or  if you want a minimum of one character     s   0-9a-zA-Z    s     Square brackets indicate a set of characters     is start of input     is end of input  or newline  depending on your options     s is whitespace   The whitespace before and after is optional   The parentheses are the grouping operator to allow you to extract the information you want   EDIT  removed my erroneous use of the  w character set

User · Answer

a-zA-Z0-9  -        the above regex allows spaces in side a  string and restrict special characters It Only allows  a-z  A-Z  0-9  Space  Underscore and dash

User · Answer

s   0-9a-zA-Z    s     or  if you want a minimum of one character     s   0-9a-zA-Z    s     Square brackets indicate a set of characters     is start of input     is end of input  or newline  depending on your options     s is whitespace   The whitespace before and after is optional   The parentheses are the grouping operator to allow you to extract the information you want   EDIT  removed my erroneous use of the  w character set

User · Answer

a-zA-Z0-9  -        the above regex allows spaces in side a  string and restrict special characters It Only allows  a-z  A-Z  0-9  Space  Underscore and dash

User · Answer

Use the word character class  The following is equivalent to a   a-zA-Z0-9         w     Explanation      start of string  w any word character  A-Z  a-z  0-9        end of string   Use     w    g if you don t want to match the underscore

User · Answer

Use the word character class  The following is equivalent to a   a-zA-Z0-9         w     Explanation      start of string  w any word character  A-Z  a-z  0-9        end of string   Use     w    g if you don t want to match the underscore

User · Answer

Save this constant  const letters      a-zA-Z0-9       now  for checking part use  match    const string    Hey there        get string from a keyup listner let id         iterate through each letters for  var i   0  i  lt  string length  i        if  string i  match letters          id    string i      else          In case you want to replace with something else     id     -          return id

User · Answer

Question is old  but it s never too late to answer    document  ready function         prevent paste   var usern paste   document getElementById  yourid      usern paste onpaste   e   gt  e preventDefault         prevent copy   var usern drop   document getElementById  yourid      usern drop ondrop   e   gt  e preventDefault             yourid   keypress function  e      var regex   new RegExp  quot   a-zA-Z0-9 s  quot      var str   String fromCharCode  e charCode   e which   e charCode     if  regex test str           return true        e preventDefault      return false

User · Answer

Instead of checking for a valid alphanumeric string  you can achieve this indirectly by checking the string for any invalid characters  Do so by checking for anything that matches the complement of the valid alphanumeric string      a-z d  i       Here is an example   var alphanumeric    someStringHere   var myRegEx       a-z d  i  var isValid     myRegEx test alphanumeric      Notice the logical not operator at isValid  since I m testing whether the string is false  not whether it s valid

User · Answer

It seems like many users have noticed this these regular expressions will almost certainly fail unless we are strictly working in English  But I think there is an easy way forward that would not be so limited    make a copy of your string in all UPPERCASE make a second copy in all lowercase   Any characters that match in those strings are definitely not alphabetic in nature   let copy1   originalString toUpperCase    let copy2   originalString toLowerCase    for let i 0  i lt originalString length  i          let bIsAlphabetic    copy1 i     copy2 i        Optionally  you can also detect numerics by just looking for digits 0 to 9

User · Answer

Question is old  but it s never too late to answer    document  ready function         prevent paste   var usern paste   document getElementById  yourid      usern paste onpaste   e   gt  e preventDefault         prevent copy   var usern drop   document getElementById  yourid      usern drop ondrop   e   gt  e preventDefault             yourid   keypress function  e      var regex   new RegExp  quot   a-zA-Z0-9 s  quot      var str   String fromCharCode  e charCode   e which   e charCode     if  regex test str           return true        e preventDefault      return false

[javascript] RegEx for Javascript to allow only alphanumeric

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