Functions in custom function default arguments

[zendak]

Sorry about the confusing subject line.
I've been looking around but couldn't find an answer to this.

Is it possible to pass a function to an argument variable of a custom function? i.e. something like this:

function getDateString($ts = time()) { 
 if (!isset($ts)) { 
  $ts = time(); 
 } 
 return date('d.m.Y H:i:s', $ts); 
 } 

If the function is called without an argument, it should default to the current timestamp. This throws a syntax error (expecting ')'), though.

Is it really only possible to pass a string or number as the default argument, instead of a function?

[jamie]

hi,

can you not take out the time() call and simply pass $ts to the function, calling it like this if it has no value

$ts = 0;
getDateString($ts);

your function then looks like this

function getDateString($ts) {
if (!isset($ts)) {
$ts = time();
}
return date('d.m.Y H:i:s', $ts);
}

?

[jollymcfats]

Expressions can not be used as default function arguments. You can often move the expression into the function to the same effect:

function getDateString($ts = null) {  
  if ($ts == null) 
    $ts = time(); 
  return date('d.m.Y H:i:s', $ts); 
}

[zendak]

Thank you, both solutions make sense. Assigning a NULL value to the default and then doing a check on that is what I need.