How do I check that a number is float or integer?

Question

How to find that a number is float or integer?

1.25 --> float  
1 --> integer  
0 --> integer  
0.25 --> float
<         


        

Answer 1

For integers I use this

function integer_or_null(value) {
    if ((undefined === value) || (null === value)) {
        return null;
    }
    if(value % 1 != 0) {
        return null;
    }
    return value;
}

Answer 2

function isInt(n) 
{
    return n != "" && !isNaN(n) && Math.round(n) == n;
}
function isFloat(n){
    return n != "" && !isNaN(n) && Math.round(n) != n;
}

works for all cases.

Answer 3

Here's what I use for integers:

Math.ceil(parseFloat(val)) === val

Short, nice :) Works all the time. This is what David Flanagan suggests if I'm not mistaken.

Answer 4

var isInt = function (n) { return n === (n | 0); };

Haven't had a case where this didn't do the job.

Answer 5

THIS IS FINAL CODE FOR CHECK BOTH INT AND FLOAT

function isInt(n) { 
   if(typeof n == 'number' && Math.Round(n) % 1 == 0) {
       return true;
   } else {
       return false;
   }
} 

OR

function isInt(n) {   
   return typeof n == 'number' && Math.Round(n) % 1 == 0;   
}   

Answer 6

Why not something like this:

var isInt = function(n) { return parseInt(n) === n };