Let user type only three different characters in an input text field

Is there a way to let the user type only three cha开发者_开发技巧racters? For example, I want to only allow 3, 6 or 9 in an input text field.

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Here's a way to do it using jQuery: http://jsfiddle.net/ThiefMaster/UZJn2/

<input type="text" maxlength="1" class="only369" />



$('.only369').keyup(function(e) {
    if(this.value != '3' && this.value != '6' && this.value != '9') {
        this.value = '';   
    }
});

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A pure JS solution:

http://jsfiddle.net/ampersand/eg8Dn/

source:

<input id="number" type="number" min="3" max="9" step="3" value="3">

<script>
document.getElementById('number').addEventListener('keyup',function(ev){
    this.value=!!~['3','6','9'].indexOf(this.value) ? this.value : '';
})
</script>

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I think it might help you...

<script type="text/javascript">
function validate(e)
{
    return (e.charCode == 51 || e.charCode == 54 || e.charCode == 57)
}
</script>
<form>
<input name="name" type="text" onkeypress="return validate(event);" />
</form>

If you want to limit the number of occurences, just set the maxlength property of the input field.

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Of course. Listen for the onchange event on the input element and when the value is different from those three numbers and greater than tree, return false.

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Short answer:

"0123456789".replace(/[^369]/g, "")

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Use this plugin. It is FANTASTIC : Alphanumeric

Answer of your question is as simple as this

$('.numericInput').numeric({ichars:'0124578'});

From authors side:

Did you ever have the need to prevent users from entering certain characters into your form?

Looking at the plugins available at jQuery, I found a great plugin made by Sam Collet called Numeric.

But it was too limited, what if I'm asking the user to create a username? Or what if I need to enter a number with decimals or an IP Address? There is another great plugin called Masked Input by Josh Bush, which can also control user input by defining a mask. The problem however with that was the length of text to be inserted must be defined as well. Again, what if I needed to control input of a username? I can't tell how many characters the user will be using, and I can't force him to use just 8 characters ,so I created AlphaNumeric.

jQuery AlphaNumeric is a javascript control plugin that allows you to limit what characters a user can enter on textboxes or textareas. Have fun.

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Use onchange="this.value=this.value.replace(/[^369]/g, '')"