[SOLVED] Empty vs. Isset

[lotrfan]

I have a user form where users input float values or integers.

 

If I want to see if no value has been input, I use the empty() function.  But if I want to see if users HAVE input a value that is a float or an integer, what function should I use?

 

Thanks in Advance

[hostfreak]

Look into the following:

http://php.net/is_numeric

http://www.php.net/manual/en/function.is-float.php

http://www.php.net/manual/en/function.is-int.php

 

Example:

<?php

    $input = $_POST['input'];

    if (is_numeric($input))
    {
        if (!is_float($input) || !is_int($input))
        {
            //error msq
        }
        else
        {
            //do whatever since it is the input you want/
        }
    }
    else
    {
        //input isn't even a number... something fishy... maybe log IP?
    }

?>

[lotrfan]

Yes, I know, but if user inputs '00000123' I don't want that. I want some thing that can handle floats AND integers BUT ONLY numbers (with option of decimals of course).

 

ex (taken from the page itself)

 

<?php

is_numeric('0123'); // true, not what I want
is_numeric(0.123); // true
is_numeric('0.123'); // true
is_numeric(123); // true
is_numeric('123'); // true
is_numeric('foo'); // false

?>

[lotrfan]

Oh, just saw your edit...

 

OK, so you think I need to change from $_REQUEST to $_POST? Why?

 

And I'm going to have to use a combination of those functions to get the results I need? I thought perhaps there was a way without, but I will combine if I need to.

[hvle]

all data input into your php from POST / get are strings.

 

i.e: 123.45 will be a string of "123.45".

 

So, you can not use is_float to check if it is a float.

 

I would first use is_numeric to check if the string is a valid representation of a numeric value.

then go thru the string to check if a period (.) exist.

[kenrbnsn]

If they enter '0123' that is numeric and when you assign it to a variable, PHP will drop the leading zero.

 

Be careful when using the empty() function on fields where you expect number to be entered. If a user enters a '0' (zero), the empty() function will return a "true". I find a safer way to determine whether a field has a value is to use the strlen() function. If that returns a zero, you know the field is truly empty.

 

Ken

[lotrfan]

@hvle: So why not just stay with the $_REQUEST and go straight to is_numeric() then to is_float() and is_int()?

 

 

@Ken:  Using strlen(), I would see if string length is set to zero, right? Are values through $_REQUEST always set as srings?

 

 

[prime]

well you can use empty or !empty or !isset or isset

[hvle]

here is a little trick for your problem:

 

if (is_numeric($_POST['number']))
{
   $mynum = $_POST['number'] * 1; // you treated it as a number, php will convert to numeric
}

var_dump(is_float($mynum));
var_dump(is_int($mynum));

[kenrbnsn]

To see what happens when using the empty() function and the strlen() function, try this little script:

<?php
function test_empty($x) {
if (empty($x)) echo 'The empty function says the string <span style="font-weight:bold;color:red">' . $x . '</span> is empty<br>';
if (strlen($x) > 0) echo 'The strlen function says the string <span style="font-weight:bold;color:blue">' . $x . '</span> is <span style="font-weight:bold">NOT</span> empty<br>';
echo '<pre>' . var_export($x,true) . '</pre>';
}
test_empty('0');
test_empty(0);
?>

 

Ken

[lotrfan]

Thanks. I think I get it now.