Allow only numbers and dot in script

Question

Am using this javascript for restrict users to type only numbers and only one dot as decimal separator    lt script type  text javascript  gt   function fun AllowOnlyAmountAndDot txt                        if event keyCode  gt  47  amp  amp  event keyCode  lt  58    event keyCode    46                               var txtbx document getElementById txt                  var amount   document getElementById txt  value                 var present 0                 var count 0                  if amount indexOf     present   amount indexOf     present 1                                      alert  0                                      if amount length  2                                  if event keyCode    46                  return false                                   do                                 present amount indexOf     present                  if present  -1                                     count                     present                                                       while present  -1                  if present  -1  amp  amp  amount length  0  amp  amp  event keyCode    46                                       event keyCode 0                        alert  Wrong position of decimal point not  allowed                           return false                                   if count gt  1  amp  amp  event keyCode    46                                        event keyCode 0                        alert  Only one decimal point is allowed                           return false                                  if count  1                                   var lastdigits amount substring amount indexOf      1 amount length                   if lastdigits length gt  2                                                                alert  Two decimal places only allowed                                  event keyCode 0                                return false                                                                       return true                            else                                   event keyCode 0                        alert  Only Numbers with dot allowed                           return false                                 lt  script gt    lt td align  right  gt   lt asp TextBox ID  txtQ1gTarget  runat  server  Width  30px  CssClass  txtbx  MaxLength  6  onkeypress  return fun AllowOnlyAmountAndDot this    gt  lt  asp TextBox gt   lt  td gt    But the onkeypress this  event returns object required error in that function at this place  var amount   document getElementById txt  value    What s my mistake here

User · Answer

lt script type  text javascript  gt      function numericValidation txtvalue            var e   event    evt     for trans-browser compatibility         var charCode   e which    e keyCode          if    document getElementById txtvalue id  value                          if  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57                   return false              return true                    else                  var val   document getElementById txtvalue id  value              if charCode  46     charCode  gt  31  amp  amp   charCode  gt  47  amp  amp  charCode  lt  58                                    var points   0                              points   val indexOf      points                                       if  points  gt   1  amp  amp  charCode    46                                             return false                                                     if  points    1                                         var lastdigits   val substring val indexOf        1  val length                       if  lastdigits length  gt   2                                                alert  Two decimal places only allowed                            return false                                                          return true                            else                   alert  Only Numarics allowed                    return false                                  lt  script gt   lt form id  form1  runat  server  gt   lt div gt     lt asp TextBox ID  txtHDLLevel  MaxLength  6  runat  server  Width  33px  onkeypress  return numericValidation this       gt   lt  div gt   lt  form gt

User · Answer

Try this for multiple text fileds  using class selector    Click here for example     x000D   x000D  var checking   function event   x000D   var data   this value  x000D   if  event charCode gt   48  amp  amp  event charCode  lt   57     event charCode   46   event charCode    0   x000D    if data indexOf       gt  -1   x000D      if event charCode   46  x000D        event preventDefault    x000D      x000D    else x000D    event preventDefault    x000D      x000D   x000D   function addListener list   x000D    for var i 0 i lt list length i     x000D        list i  addEventListener  keypress  checking   x000D         x000D     x000D   var classList   document getElementsByClassName  number    x000D   addListener classList   x000D   lt  DOCTYPE html gt  x000D   lt html gt  x000D   lt head gt  x000D   lt title gt Page Title lt  title gt  x000D   lt  head gt  x000D   lt body gt  x000D     lt input type  text  class  number  value      gt  lt br gt  lt br gt  x000D     lt input type  text  class  number  value      gt  lt br gt  lt br gt  x000D     lt input type  text  class  number  value      gt  lt br gt  lt br gt  x000D     lt input type  text  class  number  value      gt  lt br gt  lt br gt  x000D   lt  body gt  x000D   lt  html gt  x000D   x000D   x000D

User · Answer

Just add the code below in your input text   onkeypress  return event charCode    46     event charCode  gt   48  amp  amp  event charCode  lt   57

User · Answer

lt input type  text  class  decimal  value      gt      decimal   keypress function evt       return     0-9      0-9      test   this  val   evt key         I think this simple solution may be

User · Answer

try This Code    x000D   x000D  var check   function evt   x000D   x000D  var data   document getElementById  num   value  x000D  if  evt charCode gt   48  amp  amp  evt charCode  lt   57     evt charCode   46   evt charCode    0   x000D  if data indexOf       gt  -1   x000D   if evt charCode   46  x000D    evt preventDefault    x000D    x000D   else x000D  evt preventDefault    x000D     x000D   x000D  document getElementById  num   addEventListener  keypress  check   x000D   lt  DOCTYPE html gt  x000D   lt html gt  x000D   lt head gt  x000D   lt title gt Page Title lt  title gt  x000D   lt  head gt  x000D   lt body gt  x000D   lt input type  text  id  num  value      gt  x000D   x000D   x000D   x000D   lt  body gt  x000D   lt  html gt  x000D   x000D   x000D

User · Answer

Instead of using this   onkeypress  return fun AllowOnlyAmountAndDot this     You should use this   onkeypress  return fun AllowOnlyAmountAndDot this id

User · Answer

This works best for me   I also apply a currency formatter on blur where the decimal part is rounded at 2 digits just in case after validating with parseFloat   The functions that get and set the cursor position are from Vishal Monpara s blog  I also do some nice stuff on focus with those functions  You can easily remove 2 blocks of code where 2 decimals are forced if you want and get rid of the set get caret functions    lt html gt   lt body gt   lt input type  text  size  30  maxlength  30  onkeypress  return numericValidation this event      gt   lt script language  JavaScript  gt      function numericValidation obj evt            var e   event    evt     for trans-browser compatibility          var charCode   e which    e keyCode                   if  charCode    46      one dot             if  obj value indexOf       gt  -1                  return false              else                     ---if the dot is positioned in the middle give the user a surprise  remember  just 2 decimals allowed                 var idx   doGetCaretPosition obj                   var part1   obj value substr 0 idx                       part2   obj value substring idx                    if  part2 length  gt  2                        obj value   part1         part2 substr 0 2                       setCaretPosition obj  idx   1                       return false                     ---                    allow one dot if not cheating                 return true                                  else if  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57       just numbers             return false                       ---just 2 decimals stubborn          var arr   obj value split        pos   doGetCaretPosition obj            if  arr length    2  amp  amp  pos  gt  arr 0  length  amp  amp  arr 1  length    2                                             return false            ---            ok it s a number         return true             function doGetCaretPosition  ctrl            var CaretPos   0       IE Support         if  document selection            ctrl focus                 var Sel   document selection createRange                 Sel moveStart   character   -ctrl value length               CaretPos   Sel text length                       Firefox support         else if  ctrl selectionStart    ctrl selectionStart     0               CaretPos   ctrl selectionStart          return  CaretPos              function setCaretPosition ctrl  pos           if ctrl setSelectionRange                        ctrl focus                ctrl setSelectionRange pos pos                     else if  ctrl createTextRange                var range   ctrl createTextRange                range collapse true               range moveEnd  character   pos               range moveStart  character   pos               range select                     lt  script gt   lt  body gt   lt  html gt

User · Answer

This function will prevent entry of anything other than numbers and a single dot    x000D   x000D  function validateQty el  evt    x000D     var charCode    evt which    evt which   event keyCode x000D      if  charCode    45  amp  amp  charCode    8  amp  amp   charCode    46   amp  amp   charCode  lt  48    charCode  gt  57   x000D          return false  x000D      if  charCode    46    x000D          if   el value   amp  amp   el value indexOf       gt   0   x000D              return false  x000D          else x000D              return true  x000D        x000D      return true  x000D      var charCode    evt which    evt which   event keyCode  x000D      var number   evt value split       x000D      if  charCode    46  amp  amp  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57     x000D          return false  x000D        x000D     x000D   lt input type  text  onkeypress  return validateQty this event    gt  x000D   x000D   x000D

User · Answer

Use Jquery instead  Add a decimal class to your textbox    lt input type  text  class  decimal  value      gt    Use this code in your JS  It checks for multiple decimals and also restrict users to type only numbers       decimal   keyup function        var val     this  val        if isNaN val             val   val replace    0-9    g               if val split      length gt 2                val  val replace                         this  val val           Check this fiddle  http   jsfiddle net 2YW8g   Hope it helps

User · Answer

function isNumber evt        evt    evt    evt   window event      var charCode    evt which    evt which   evt keyCode      if  charCode  gt  31  amp  amp   charCode  lt  46    charCode  gt  57             return false            return true      you should use this function and write the properties of this element    HTML Code    lt input id  deneme  data-mini  true  onKeyPress  return isNumber event   type  text   gt

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lt input type  text  class  form-control  id  odometer reading  name  odometer reading   placeholder  Odometer Reading  onblur  odometer reading1     onkeypress  validate event   required      gt   lt script gt                  function validate evt                      var theEvent   evt    window event                    var key   theEvent keyCode    theEvent which                    key   String fromCharCode  key                      var regex     0-9                         if   regex test key                          theEvent returnValue   false                      if theEvent preventDefault  theEvent preventDefault                                                       lt  script gt

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x000D   x000D  function isNumberKey evt id  x000D    x000D   try  x000D          var charCode    evt which    evt which   event keyCode  x000D     x000D          if charCode  46   x000D              var txt document getElementById id  value  x000D              if   txt indexOf       gt  -1    x000D    x000D                  return true  x000D                x000D            x000D          if  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57    x000D              return false  x000D   x000D          return true  x000D    catch w   x000D    alert w   x000D     x000D    x000D   lt html gt  x000D     lt head gt  x000D     lt  head gt  x000D     lt body gt  x000D       lt INPUT id  txtChar  onkeypress  return isNumberKey event this id   type  text  name  txtChar  gt  x000D     lt  body gt  x000D   lt  html gt  x000D   x000D   x000D

User · Answer

lt script type  text Javascript  gt          function checkDecimal inputVal                var ex      0-9      0-9                  if  ex test inputVal value     false                    inputVal value   inputVal value substring 0  inputVal value length - 1                            lt  script gt

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Hope this could help someone   document  on  quot input quot    quot  numeric quot   function     this value   this value match    d     d 0 2

User · Answer

You can use this  Javascript  function isNumber evt        evt    evt    evt   window event      var charCode    evt which    evt which   evt keyCode      if  charCode  gt  31  amp  amp   charCode  lt  48    charCode  gt  57  amp  amp  charCode  46             return false            return true      Usage     lt input onkeypress  return isNumber event   class  form-control  gt

User · Answer

This is a great place to use regular expressions   By using a regular expression  you can replace all that code with just one line   You can use the following regex to validate your requirements    0-9      0-9    In other words  zero or more numeric characters  followed by zero or one period s    followed by zero or more numeric characters   You can replace your code with this   function validate s        var rgx      0-9      0-9          return s match rgx       That code can replace your entire function    Note that you have to escape the period with a backslash  otherwise it stands for  any character     For more reading on using regular expressions with javascript  check this out    http   www regular-expressions info javascript html   You can also test the above regex here    http   www regular-expressions info javascriptexample html     Explanation of the regex used above    The brackets mean  any character inside these brackets   You can use a hyphen  like above  to indicate a range of chars    The   means  zero or more of the previous expression    0-9   means  zero or more numbers  The backslash is used as an escape character for the period  because period usually stands for  any character     The   means  zero or one of the previous character   The   represents the beginning of a string  The   represents the end of a string  Starting the regex with   and ending it with   ensures that the entire string adheres to the regex pattern    Hope this helps

[javascript] Allow only numbers and dot in script

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