Question

<?php     /* Copyright Date --------------------------*/ function copyright_date($creation_year) {     $current_year = date('Y');      if ($creation_year == $current_year || $creation_year == '') {         echo $current_year;     }      else {         echo $creation_year . '-' . $current_year;     }            } ?> 

If someone forgets to add the argument (the year the website was created), e.g.

<?php copyright_date(); ?> 

instead of:

<?php copyright_date(2009); ?> 

how would I test to see if the argument was left blank? In my if statement, that’s what $creation_year == ” is for, but since the argument isn’t a string, it doesn’t work.

Answer 1

Make $creation_year an optional argument with a default value of NULL.

function copyright_date($creation_year=NULL) { 

Now inside the function just test if $creation_year is equal to NULL, which will happen when the function is called with no arguments.