Checking if field is empty

Sharif

I know you can do:

if(!isset($_POST['field']) || empty($_POST['field']))
{
echo 1234;
}

To check if a form field is empty on input, but what about if there are just spaces in the input? Then my error message will not display. How do I check against that?

drew010

if(!isset($POST['field']) || empty(trim($POST['field'])))

trim strips whitespace off the beginning and end of a string. so three blank spaces as a string would but cut to 0 characters after running trim

Sharif

This doesn't seem to work. Here is my code (I had to call trim() before empty() to avoid parse errors):

if(!isset($_GET['k']) || trim(empty($_GET['k'])
))
{
echo 1234;
}

It won't output '1234' if the var is empty.

bubblenut

You don't have to call trim first, the parse error must have been something else. What was the error message?

sidney

here a couple of methods as you cant use trim with empty

 $k="   ";
if(!isset($k) || trim($k)=="" 
) 
{ 
echo 1234; 

//or

if(isset($_GET['k']))
	{ 
	trim($_GET['k']); 
	if(empty($_GET['k']))
		{ 
		echo "empty"; 
		}
	}
else echo"not set";

Sharif

I don't get why trim() isnt working? Maybe because how the characters are in the URL? If it's spaces, the characters are:

/page.php?k=+++++

represents the spaces apparently!

keith73

/**************************************
function : stringIsEmpty
description : checks the field length
return value: BOOL
parameters : 1
string = STRING:the string to check
**************************************/

function stringIsEmpty($string)
{
if (strlen(trim($string)) < 1){
return(TRUE);
} else {
return(FALSE);
}//end if
}//END function stringIsEmpty

if ( stringIsEmpty($_POST['field']){
//do something here
}//end if

Sharif

YES!! It worked! Still a mystery why just trim() didn't work...

Weedpacket

[man]empty[/man]
Note: empty() only checks variables as anything else will result in a parse error. In other words, the following will not work: empty(addslashes($name))