How do you IF with a null value

Good Morning All,

What I am trying to do is to fill $col12 with "None" if there is a NULL returned from the database.

I have tried;

if ($col12="")
{
$col12 == "None";
}

but I take it that "" is not a null, it is nothing (someone did explain to me that NULL and nothing are two completely different things!!).

I'm sure it is simple.

Regards,

Neil.

if ($col12="")
{
$col12 == "None";
}

should actually be:

if ($col12 == "") 
{ 
	$col12 = "None"; 
}

It might be better to compare with NULL, or to use isset()

A NULL value is indeed a nothing value.

I'd go for the isset syntax

If (isset $coll2)
{
Do your thing right here
}

Isset means that the variable that you name excist yes or no

If you use the above syntax it says "do what's between the {} tags if the variable $coll2 excists"

I wonder: If you take a textfield, submit the conent of this texfield, but leave the textfield blank... What would you get.. a "" or a NULL ??

Actually, isset() returns false if the variable is undefined or NULL
It returns true on all other cases.

You should use:

if (isset($coll2))
{
	$col12 = "None";
}

Although isset() is a language construct, the parentheses are required.

I wonder: If you take a textfield, submit the conent of this texfield, but leave the textfield blank... What would you get.. a "" or a NULL ??

They should be the same.

The difference should lie between NULL and a null byte

actually, an undefined variable (or unset variable) is also null, so my "if the variable is undefined" part is a little redundant.

meaning

Null == "" == !isset

?? 😕

I think that, being a language construct, isset() is a little different.