Restrict numbers and limit them to two

Question

How to restrict my text field to numbers only and limit them in two with a single function.

Text fields have a "maxsize" attribute, no JS needed. Check google for "textfield limit numbers" for a gazillion tutorials. — , Apr 07 '11 at 08:28
http://stackoverflow.com/questions/995183/how-to-allow-only-numeric-0-9-in-html-inputbox-using-jquery — Amr Elgarhy, Apr 07 '11 at 08:29
Perhaps the OP wants to dynamically change the maximum number of characters allowed in a field. I could conceive of a use for this. — Oren Hizkiya, Apr 07 '11 at 08:36
@theJava -- There seems to be a lot of different interpreations being made of what you want. Perhaps you could edit the question to make it more clear exactly what you're trying to achieve. You may get more helpful answers. — Spudley, Apr 07 '11 at 08:57

score 2 · Answer 1 · edited Dec 30 '13 at 19:03

2

For limiting them to enter only 2 char use maxlength attribute of input. To check enter string is number or not user isNaN(str) function.

edited Dec 30 '13 at 19:03

BenMorel

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answered Apr 07 '11 at 08:28

Harry Joy

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score 2 · Answer 2 · answered Apr 07 '11 at 10:43

2

Since no one has suggested a regular expression, I will. :-)

var re = /^-?\d{1,2}$/;
if (re.test(input.value)) {
  // number is one or two digits with optional leading minus
} else {
  // it's not
}

answered Apr 07 '11 at 10:43

RobG

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score 1 · Accepted Answer · edited May 15 '13 at 07:18

1

<script type="text/javascript">
    function ValidateField(FieldName){

        // Get fields value
        var FieldVal = document.GetElementById(FieldName).value;

        // Check it's a number, and then check it's range is correct
        // Alternatively you could do FieldVal.length
        if(!isNaN(FieldVal) && (FieldVal < 100 && FieldVal > -100))
            alert("Valid!");
        else
            alert("Invalid");
    }
</script>    

<input type="text" name="MyField" />
<button onclick="ValidateField('MyField')">Test</button>

I've interpreted 'limit to 2' to mean a number ranging from -99 to 99.

edited May 15 '13 at 07:18

okm

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answered Apr 07 '11 at 08:31

Tom Gullen

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Why limit it in JS while we have attribute in input tag itself. – Harry Joy Apr 07 '11 at 08:33
Because of minus symbols and plus symbols. -99 is 3 length, but OP might want that to pass as valid. – Tom Gullen Apr 07 '11 at 08:37
regarding the interpretation of allowing the minus sign: the question it too vague to make that kind of assumption. – Spudley Apr 07 '11 at 08:55

score 1 · Answer 4 · answered Apr 07 '11 at 08:43

1

In HTML5 you can just use: <input type="number" />

answered Apr 07 '11 at 08:43

Corneliu

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score 1 · Answer 5 · answered Apr 07 '11 at 08:44

1

If you are using jquery:

$('#myTextAreaID').keydown(function(event) {
  if (event.target.length >1 || event.keyCode < 48 || event.keyCode > 57) {
     event.preventDefault();
   }
});

if you want it to work with the numeric keypad, you will need to also allow keycodes 96 to 105

answered Apr 07 '11 at 08:44

herostwist

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thinking further this may be better: event.target.length >1 || String.fromCharCode(event.keyCode).match(/\D/); – herostwist Apr 07 '11 at 09:47

Restrict numbers and limit them to two

5 Answers5

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