HTML text input allow only numeric input

Question

Is there a quick way to set an HTML text input () to only allow numeric keystrokes (plus \'.\')?

Answer 1

I saw some great answers however I like them as small and as simple as possible, so maybe someone will benefit from it. I would use javascript Number() and isNaN functionality like this:

if(isNaN(Number(str))) {
   // ... Exception it is NOT a number
} else {
   // ... Do something you have a number
}

Hope this helps.