HTML Text Input allow only Numeric input

Use this DOM

<input type='text' onkeypress='validate(event)' />

And this script

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();
  }
}

I've searched long and hard for a good answer to this, and we desperately need <input type="number", but short of that, these 2 are the most concise ways I could come up with:

<input type="text" 
       onkeyup="this.value=this.value.replace(/[^\d]/,'')">

If you dislike the non-accepted character showing for a split-second before being erased, the method below is my solution. Note the numerous additional conditions, this is to avoid disabling all sorts of navigation and hotkeys. If anyone knows how to compactify this, let us know!

<input type="text" 
onkeydown="return ( event.ctrlKey || event.altKey 
                    || (47<event.keyCode && event.keyCode<58 && event.shiftKey==false) 
                    || (95<event.keyCode && event.keyCode<106)
                    || (event.keyCode==8) || (event.keyCode==9) 
                    || (event.keyCode>34 && event.keyCode<40) 
                    || (event.keyCode==46) )">

HTML5 has <input type=number>, which sounds right for you. Currently, only Opera supports it natively, but there is a project that has a JavaScript implementation.

And one more example, which works great for me:

function validateNumber(event) {
    var key = window.event ? event.keyCode : event.which;

    if (event.keyCode === 8 || event.keyCode === 46
     || event.keyCode === 37 || event.keyCode === 39) {
        return true;
    }
    else if ( key < 48 || key > 57 ) {
        return false;
    }
    else return true;
};

Also attach to keypress event

$(document).ready(function(){
    $('[id^=edit]').keypress(validateNumber);
});

And html:

<input type="input" id="edit1" value="0" size="5" maxlength="5" />

Update:

Here is jsfiddle example

I opted to use a combination of the two answers mentioned here i.e.

<input type="number" />

and

function isNumberKey(evt){
    var charCode = (evt.which) ? evt.which : evt.keyCode
    return !(charCode > 31 && (charCode < 48 || charCode > 57));
}

<input type="text" onkeypress="return isNumberKey(event);">

Most answers here all have the weakness of using key- events.

Many of the answers would limit your ability to do text selection with keyboard macros, copy+paste and more unwanted behavior, others seem to depend on specific jQuery plugins, which is killing flies with machineguns.

This simple solution seems to work best for me cross platform, regardless of input mechanism (keystroke, copy+paste, rightclick copy+paste, speech-to-text etc.). All text selection keyboard macros would still work, and it would even limit ones ability to set a non-numeric value by script.

function forceNumeric(){
    var $input = $(this);
    $input.val($input.val().replace(/[^\d]+/g,''));
}
$('body').on('propertychange input', 'input[type="number"]', forceNumeric);

HTML5 supports regexes, so you could use this:

<input id="numbersOnly" pattern="[0-9.]+" type="text">

Warning: Some browsers don't support this yet.

so simple.... // In Javascript Function (can use HTML or PHP).

function isNumberKey(evt){
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;
    return true;
}

In Your Form Input :

<input type=text name=form_number size=20 maxlength=12 onkeypress='return isNumberKey(event)'>

With input max. (these above, is allow for 12 Digit number)

2 solutions:

Use a form validator (for example with jQuery validation plugin)

Do a check during the onblur (i.e. when the user leaves the field) event of the input field, with the regular expression:

<script type="text/javascript">
function testField(field) {
    var regExpr = new RegExp("^\d*\.?\d*$");
    if (!regExpr.test(field.value)) {
      // Case of error
      field.value = "";
    }
}

</script>

<input type="text" ... onblur="testField(this);"/>

JavaScript

function validateNumber(evt) {
    var e = evt || window.event;
    var key = e.keyCode || e.which;

    if (!e.shiftKey && !e.altKey && !e.ctrlKey &&
    // numbers   
    key >= 48 && key <= 57 ||
    // Numeric keypad
    key >= 96 && key <= 105 ||
    // Backspace and Tab and Enter
    key == 8 || key == 9 || key == 13 ||
    // Home and End
    key == 35 || key == 36 ||
    // left and right arrows
    key == 37 || key == 39 ||
    // Del and Ins
    key == 46 || key == 45) {
        // input is VALID
    }
    else {
        // input is INVALID
        e.returnValue = false;
        if (e.preventDefault) e.preventDefault();
    }
}

additional you could add comma, period and minus (,.-)

  // comma, period and minus, . on keypad
  key == 190 || key == 188 || key == 109 || key == 110 ||

HTML

<input type="text" onkeydown="validateNumber(event);"/ >

If you want to suggest to the device(maybe a mobile phone) between alpha or numeric you can use <input type="number">

A short and sweet implementation using jQuery and replace() instead of looking at event.keyCode or event.which:

$('input.numeric').live('keyup', function(e) {
  $(this).val($(this).val().replace(/[^0-9]/g, ''));
});

Only small side effect that the typed letter appears momentarily and CTRL/CMD + A seems to behave a bit strange.

if you just want to only allow numbers 0-9 on a input, you can just remove all non numeric characters, without messing about charCodes and arrows ctrl and others kinds of keyboars, and this fix a string pasted or draged to a input.

this have a advantage that you don't have to worry about browser messy of keyEvents. you can use this to allow letters and -,. but this cant deal with valid numbers like (0.1.4- is not a integer nor float), in this case this others guys solutions is better.

LIVE DEMO

<input type="text" id="number" size="100" value="type a number here">

Javascript

addEvent(document.getElementById('number'),'keyup',validate);
addEvent(document.getElementById('number'),'mouseover',validate);

function validate(event){   
    var charsAllowed="0123456789";
    var allowed;
    for(var i=0;i<this.value.length;i++){       
        allowed=false;
        for(var j=0;j<charsAllowed.length;j++){
            if( this.value.charAt(i)==charsAllowed.charAt(j) ){ allowed=true; }
        }
        if(allowed==false){ this.value = this.value.replace(this.value.charAt(i),""); i--; }
    }
    return true;
}

yes, regex is less work but not faster than this.

<input name="amount" type="text" value="Only number in here"/> 

<script>
    $('input[name=amount]').keyup(function(){
        $(this).val($(this).val().replace(/[^\d]/,''));
    });
</script>

<input id="numbers" pattern="[0-9.]+" type="number">

you can use pattern for this. here you can see the complete mobile website interface tips

input type="number" is html5 attribute.

In other case this will help you.

function isNumberKey(evt){
    var charCode = (evt.which) ? evt.which : evt.keyCode
    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;
    return true;
}

<input type="number" name="somecode" onkeypress="return isNumberKey(event)"/>

Just an other variant with jQuery using

$(".numeric").keypress(function() {
    return (/\d/.test(String.fromCharCode(event.which) ))
});

This is the extended version of geowa4's solution. Supports min and max attributes. If the number is out of range, the previous value will be shown.

You can test it here.

Usage: <input type=text class='number' maxlength=3 min=1 max=500>

function number(e) {
var theEvent = e || window.event;
var key = theEvent.keyCode || theEvent.which;
if(key!=13&&key!=9){//allow enter and tab
  key = String.fromCharCode( key );
  var regex = /[0-9]|\./;
  if( !regex.test(key)) {
    theEvent.returnValue = false;
    if(theEvent.preventDefault) theEvent.preventDefault();
    }   
  }
}

$(document).ready(function(){
    $("input[type=text]").filter(".number,.NUMBER").on({
        "focus":function(e){
         $(e.target).data('oldValue',$(e.target).val());
            },
        "keypress":function(e){
                e.target.oldvalue = e.target.value;
                number(e);
            },
        "change":function(e){
            var t = e.target;
            var min = $(t).attr("min");
            var max = $(t).attr("max");
            var val = parseInt($(t).val(),10);          
            if( val<min || max<val)
                {
                    alert("Error!");
                    $(t).val($(t).data('oldValue'));
                }

            }       
    });     
});

If the inputs are dynamic use this:

$(document).ready(function(){
    $("body").on("focus","input[type=text].number,.NUMBER",function(e){
        $(e.target).data('oldValue',$(e.target).val());
    }); 
    $("body").on("keypress","input[type=text].number,.NUMBER",function(e){
        e.target.oldvalue = e.target.value;
        number(e);
    }); 
    $("body").on("change","input[type=text].number,.NUMBER",function(e){
        var t = e.target
        var min = $(t).attr("min");
        var max = $(t).attr("max");
        var val = parseInt($(t).val());         
        if( val<min || max<val)
            {
                alert("Error!");
                $(t).val($(t).data('oldValue'));
            }
    }); 
});

Lots of great answers here but thought I'd contribute this simple one which allows for exactly one decimal but no more:

<input type="text" oninput="this.value = this.value.replace(/[^0-9.]/g, ''); this.value = this.value.replace(/(\..*)\./g, '$1');" />

this is an improved function :

function validateNumber(evt) {
  var theEvent = evt || window.event;
  var key = theEvent.keyCode || theEvent.which;
  if ((key < 48 || key > 57) && !(key == 8 || key == 9 || key == 13 || key == 37 || key == 39 || key == 46) ){
    theEvent.returnValue = false;
    if (theEvent.preventDefault) theEvent.preventDefault();
  }
}

You can also compare input value (which is treated as string by default) to itself forced as numeric, like:

if(event.target.value == event.target.value * 1) {
    // returns true if input value is numeric string
}

However, you need to bind that to event like keyup etc.

You can replace the Shurok function with:

$(".numeric").keypress(function() {
    return (/[0123456789,.]/.test(String.fromCharCode(Event.which) ))
});

Javascript code:

function validate(evt)

 {

  if(evt.keyCode!=8)

  {

  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();

  }

  }

}

HTML code:

<input type='text' name='price' value='0' onkeypress='validate(event)'/>

works perfectly because backspace keycode is 8 and regex expression doesnt let it so its a easy way to bypass the bug :)

The best way (allow ALL type of numbers - real negative, real positive, iinteger negative, integer positive) is:

$(input).keypress(function (evt){
    var theEvent = evt || window.event;
    var key = theEvent.keyCode || theEvent.which;
    key = String.fromCharCode( key );
    var regex = /[-\d\.]/; // dowolna liczba (+- ,.) :)
    var objRegex = /^-?\d*[\.]?\d*$/;
    var val = $(evt.target).val();
    if(!regex.test(key) || !objRegex.test(val+key) || 
            !theEvent.keyCode == 46 || !theEvent.keyCode == 8) {
        theEvent.returnValue = false;
        if(theEvent.preventDefault) theEvent.preventDefault();
    };
}); 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Allow Only Numbers
</HEAD>

<BODY>
<script language="JavaScript">
function onlyNumbers(evt)
{
var e = event || evt; // for trans-browser compatibility
var charCode = e.which || e.keyCode;

if (charCode > 31 && (charCode < 48 || charCode > 57))
    return false;

return true;

}
</script>
<input type="text" onkeypress="return onlyNumbers();">
</BODY>
</HTML>

another easy way with jquery:

     $('.Numeric').bind('keydown',function(e){
             if (e.which < 48 ||  e.which > 57)
                return false;
                return true;
       })           

now just set your each inputs class to Numeric, like:

     <input type="text" id="inp2" name="inp2" class='Numeric' />

How about this DOM...

<input type = "text" onkeydown = "validate(event)"/>

...and this script?

validate = function(evt)
{
    if ([8, 46, 37, 39, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 35, 36].indexOf(evt.keyCode || evt.which) == -1)
    {
        evt.returnValue = false;
        if(evt.preventDefault){evt.preventDefault();}
    }
}

...OR this script, without indexOf, using 2 for's...

validate = function(evt)
{
    var CharValidate = new Array("08", "046", "039", "948", "235");
    var number_pressed = false;
    for (i = 0; i < 5; i++)
    {
        for (Ncount = 0; Ncount < parseInt(CharValidate[i].substring(0, 1)) + 1; Ncount++)
        {
            if ((evt.keyCode || evt.which) == parseInt(CharValidate[i].substring(1, CharValidate[i].lenght)) + Ncount)
            {
                number_pressed = true;
            }
        }
    }
    if (number_pressed == false)
    {
        evt.returnValue = false;
        if(evt.preventDefault){evt.preventDefault();}
    }
}

I used the onkeydown attribute instead of onkeypress because the onkeydown attribute is checked before onkeypress attribute. The problem would be in the google chrome browser.

With the attribute "onkeypress", TAB would be uncontrollable with "preventDefault" on google chrome, however, with the attribute "onkeydown", TAB becomes controllable!

ASCII Code for TAB => 9

The first script have less code than the second, however, the array of ASCII characters must have all the keys.

The second script is much bigger than the first, but the array does not need all keys, the first digit in each position of the array is the number of times each position will be readed. For each reading, will be incremented 1 to the next one. For example:




NCount = 0

48 + NCount = 48

NCount + +

48 + NCount = 49

NCount + +

...

48 + NCount = 57




In the case of numerical keys are only 10 (0 - 9), but if they were 1 million would not make sense to create an array with all these keys.

ASCII Codes:

• 8 ==> (Backspace);
• 46 => (Delete);
• 37 => (left arrow);
• 39 => (right arrow);
• 48 - 57 => (numbers);
• 36 => (home);
• 35 => (end);

I'm gonna sleep now!!

This is my first post on StackOverflow :P

Give the input field a class (<input class="digit" ...> ) and use jquery as below .

jQuery(document).ready(function () {
            jQuery('input.digit').live('input keyup',function(e){ jQuery(this).val(jQuery(this).val().replace( /[^\d]/g ,'')); });
});

Above code also works to disable special characters in Ctrl+V strokes and right click strokes also.

Remember the regional differences (Euros use periods and commas in the reverse way as Americans), plus the minus sign (or the convention of wrapping a number in parentheses to indicate negative), plus exponential notation (I'm reaching on that one).