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 ```

Accepted Answer

check for a remainder when dividing by 1:

```
function isInt(n) {
   return n % 1 === 0;
}
```

If you don't know that the argument is a number you need two tests:

```
function isInt(n){
    return Number(n) === n && n % 1 === 0;
}

function isFloat(n){
    return Number(n) === n && n % 1 !== 0;
}
```

Update 2019 5 years after this answer was written, a solution was standardized in ECMA Script 2015. That solution is covered in this answer.

Solution