Using ==, if statement not returning true.

Nibinaear

This is part of my script to print out everything into a table with two columns:


$lengthOfData = strlen($column[$i]);
//	echo $lengthOfData;

if($lengthOfData == 0)
{
//there is normally an ampersand followed by a 
//nbsp ; in the quotes underneath, 
//but the forums took it as meaning 
//a space directly, despite the code tags.

  echo "&nbsp;";     
}
else
{
  echo "$column[i]";  
}

I'm trying to test whether the db table cell contains nothing. I.e. is null, in which case there needs to be a spacer put into the html table to make it display correctly. Otherwise the html table cell contains the data.

Sadly the if statement is not returning true, i.e. lengthOfData is not returning 0 even thought I've tested it, and it is.

Does this have something to do with the scope of the variable, is the lengthOfData available to the if statement?

Roger_Ramjet

Well, if the database column contains NULL then your length bit is pretty meaningless. The good thing is that NULL evaluates to FALSE so the construct is simplified


if (!column[$i]) {
   echo ' ';
}
else {
   echo column[$i];
}

I've seen some people disdain the use of NULL for empty columns and assert that you should always define text cols as NOT NULL. Me, I'm used to using them in Access where they are very usefull when printing as null automatically suppresses the display of an empty field in Access Reports so addresses etc don't appear with gaps between the lines. I also like the way they evaluate to false as above. Very clean codeing and a very handy tool is the good old NULL.

Nibinaear

It's okay, I've fixed it now, it was the dollar signs again, why do we have to use them!

Roger_Ramjet

I would not guarantee my syntax in php, I'm still making getting used to it again after 4 years of solid VB & VBA. But I'm sure you'll get the idea: if the column is null then it's false, however you actaully code that in php syntax.

Installer

What was the error with the dollar signs? They look ok to me.

Nibinaear

Basically, I've got a:


//If a table cell contains nothing, the script prints a spacer into the cell.
if($column[$i] == "")
{
  echo "&nbsp;";     
}
else
{    
  echo $column[$i];
}

Before the code was doing an, "i", instead of a, "$i" for the $column bit at the end. You can't see that at the end of the previous post because it was displayed wrongly.

Installer

Right--we all should have caught that sooner. 🙂