I'd like to validate an input field within a preconfigured range of numbers. Only numbers from 1 up to 24 are allowed.

How can I do?

With a custom solution like this:

    $('.field').keypress(function(event) {
        var val = parseInt($(this).val()) + HERE_I_SHOULD_SUM_THE_NEWLY_ADDED_DIGIT;
        if(val < 1 || val > 24) event.preventDefault();
    });

I'm able to retrieve the current input value. How can I add the newly added digit?

I'd like to validate an input field within a preconfigured range of numbers. Only numbers from 1 up to 24 are allowed.

How can I do?

With a custom solution like this:

    $('.field').keypress(function(event) {
        var val = parseInt($(this).val()) + HERE_I_SHOULD_SUM_THE_NEWLY_ADDED_DIGIT;
        if(val < 1 || val > 24) event.preventDefault();
    });

I'm able to retrieve the current input value. How can I add the newly added digit?

• javascript
• jquery

5 Answers 5

How about something like this?

​$("input").on("change", function() {
    var val = Math.abs(parseInt(this.value, 10) || 1);
    this.value = val > 25 ? 24 : val;
});​​​​​​​​​​​​​

DEMO: http://jsfiddle.net/3jw4S/

There are builtin functionalities for inputs in modern browsers:

A comprehensive overview can be found here: http://www.the-art-of-web.com/html/html5-form-validation/

Basically, you could write:

<input type="number" min="1" max="24" step="1" required>

with pattern you can define regular expressions to test against:

pattern="\d[0-3]"

Example

There's a plugin for JQuery that can help you with validation called Valid8:

http://unwrongest.com/projects/valid8/

You will need to use a regular expression such as this one:

^([1-9]|[1]?[1-9]?|[2][0-4]|10)$

function validateForm()
{
var x=document.forms["myForm"]["fname"].value;
if (x==null || x <1|| x >24)
  {
  alert("Value must be between 1 & 24");
  return false;
  }
}

Something along those lines should work

Try this

function validate() {
 var x = parseInt(value,10) // its the value from the input box;
 if(isNaN(x)||x<1||x>24)
 {
  alert("Value must be between 1 and 24");
  return false;
  }
}