Question

I want to validate that the value entered by a user in a textbox is a multiple of 100 using jQuery. How can I do that?

Answer 1

There are a lot of fun ways. Lets collect the input value itself:

var input = $('#textbox').val();

So, ways:

1. The boring right way

   if (parseInt(input,10) % 100 === 0)
   

2. A bit more fun way

   if (input.substr(-2)==='00')
   

3. “I love odd bases”

   if (parseInt(value,13) % parseInt('79',13) === 0)
   

4. Regexes

   if (input.match(/[1-9]+00$/))
   

5. More fun (but definitely more robust) regexes

   if (input.match(/\s*\d+0{2}\s*$/))
   

6. And the winner is…

   if ((input.search(/\s*\d+0{2}\s*$/)==-1?"false":"true" !== "false"))
   

But if I were you I’d stop with first way. 🙂