Check if number is decimal

Question

I need to check in PHP if user entered a decimal number (US way, with decimal point: X.XXX)

Any reliable way to do this?

Answer 1

I was passed a string, and wanted to know if it was a decimal or not. I ended up with this:

function isDecimal($value) 
{
     return ((float) $value !== floor($value));
}

I ran a bunch of test including decimals and non-decimals on both sides of zero, and it seemed to work.

Answer 2

is_numeric returns true for decimals and integers. So if your user lazily enters 1 instead of 1.00 it will still return true:

echo is_numeric(1); // true
echo is_numeric(1.00); // true

You may wish to convert the integer to a decimal with PHP, or let your database do it for you.

Answer 3

You can get most of what you want from is_float, but if you really need to know whether it has a decimal in it, your function above isn't terribly far (albeit the wrong language):

function is_decimal( $val )
{
    return is_numeric( $val ) && floor( $val ) != $val;
}

Answer 4

Simplest solution is

if(is_float(2.3)){

 echo 'true';

}

Answer 5

another way to solve this: preg_match('/^\d+\.\d+$/',$number); :)

Answer 6

Maybe try looking into this as well

!is_int()