How can I limit possible inputs in a HTML5 “number

Question

For <input type="number"> element, maxlength is not working. How can I restrict the maxlength for that number element?

Answer 1

You can specify the min and max attributes, which will allow input only within a specific range.

<!-- equivalent to maxlength=4 -->
<input type="number" min="-9999" max="9999">

This only works for the spinner control buttons, however. Although the user may be able to type a number greater than the allowed max, the form will not submit.

^{Screenshot taken from Chrome 15}

You can use the HTML5 oninput event in JavaScript to limit the number of characters:

myInput.oninput = function () {
    if (this.value.length > 4) {
        this.value = this.value.slice(0,4); 
    }
}

Answer 2

As with type="number", you specify a max instead of maxlength property, which is the maximum possible number possible. So with 4 digits, max should be 9999, 5 digits 99999 and so on.

Also if you want to make sure it is a positive number, you could set min="0", ensuring positive numbers.

Answer 3

Another option is to just add a listener for anything with the maxlength attribute and add the slice value to that. Assuming the user doesn't want to use a function inside every event related to the input. Here's a code snippet. Ignore the CSS and HTML code, the JavaScript is what matters.

// Reusable Function to Enforce MaxLength
function enforce_maxlength(event) {
  var t = event.target;
  if (t.hasAttribute('maxlength')) {
    t.value = t.value.slice(0, t.getAttribute('maxlength'));
  }
}

// Global Listener for anything with an maxlength attribute.
// I put the listener on the body, put it on whatever.
document.body.addEventListener('input', enforce_maxlength);

label { margin: 10px; font-size: 16px; display: block }
input { margin: 0 10px 10px; padding: 5px; font-size: 24px; width: 100px }
span { margin: 0 10px 10px; display: block; font-size: 12px; color: #666 }

<label for="test_input">Text Input</label>
<input id="test_input" type="text" maxlength="5"/>
<span>set to 5 maxlength</span>

<br>

<label for="test_input">Number Input</label>
<input id="test_input" type="number" min="0" max="99" maxlength="2"/>
<span>set to 2 maxlength, min 0 and max 99</span>

Answer 4

You can specify it as text, but add pettern, that match numbers only:

<input type="text" pattern="\d*" maxlength="2">

It works perfect and also on mobile ( tested on iOS 8 and Android ) pops out the number keyboard.

Answer 5

//For Angular I have attached following snippet.

<div ng-app="">
  <form>
    Enter number: <input type="number" ng-model="number" onKeyPress="if(this.value.length==7) return false;" min="0">
  </form>
  <h1>You entered: {{number}}</h1>
</div>

If you use "onkeypress" event then you will not get any user limitations as such while developing ( unit test it). And if you have requirement that do not allow user to enter after particular limit, take a look of this code and try once.

Answer 6

I had this problem before and I solved it using a combination of html5 number type and jQuery.

<input maxlength="2" min="0" max="59" name="minutes" value="0" type="number"/>

script:

$("input[name='minutes']").on('keyup keypress blur change', function(e) {
    //return false if not 0-9
    if (e.which != 8 && e.which != 0 && (e.which < 48 || e.which > 57)) {
       return false;
    }else{
        //limit length but allow backspace so that you can still delete the numbers.
        if( $(this).val().length >= parseInt($(this).attr('maxlength')) && (e.which != 8 && e.which != 0)){
            return false;
        }
    }
});

I don't know if the events are a bit overkill but it solved my problem. JSfiddle