Can a function return TWO values?

[El_Zagna]

Here's what I really am trying to do. Often when I call a function I want to know if it worked (return TRUE), and if it didn't I want to know what the error message is (return $ErrorMessage). It seems to me that in previous environments I could make a call like this:

if (foo())
{...}
else
{...}

If foo() returned anything other than TRUE (a string such as an error message for example) it would be evaluated as FALSE. PHP doesn't seem to work that way. Strings appear to evaluate as TRUE.

So what's a good way of getting both the TRUE/FALSE plus an error message?

[bogu]

u can return true/false/error_mess

And when u check what it has returned:

if ($return===false) 
    /* is false; */
elseif ($return===true)
    /* is true; */
else
    /* is error message ....; */

And this is only one thing, u can do it what ever u want ...

Another think u could do is to set a global var where u keep your error and the function return true/false and set the var error with the equivalent error or left it empty if there is no error ...

You can go like this on and on and on ...

You'll find your best way I just give u some ideas.

[ahundiak]

The key (as bogu's code shows) is to use === when testing for true. This will distingush between your error flag and an error message)

function whatever()
{
    if ($anError) {
        return 'Ran into an error';
    }
    return TRUE;  // Everthing hunky and dory
}
$return = whatever();
if (!$return !== TRUE) {
  // Process error
}

By the way, for PHP4 it might be better to use trigger_error(). And for PHP5, take a look at Exceptions.

[RMullen]

You can also use session variables, but this is simpler and will work, depending upon what the function does. If it's something like a db insert, it works, just fine and makes it easier to test what's going on when things break.

I do this sort of thing a lot, especially when retrieving lists and getting a count of the resulting array. It makes for a little more coding effort, but I think it's worth it for clarity.

function trySomething($sql)
{
    //insert $sql and return T/F OR set a variable
}
function trySomethingElse($sql)
{
    //insert modified $sql and return T/F OR set a variable
}

function doSomething()
{
      //optional, of course
       $indicator = array();

   //examples  not intended to work, just an idea
   $indicator[result] =  if( $this->trySomething($sql) ) ? '1' : '0';
   $indicator[result2] = $this->trySomethingElse($sql);
   $indicator[message] = $setErrorMessage($indicator[result]);
   $indicator[arraysize] = count($indicator[result]);

RETURN $indicator;
}

[Weedpacket]

Or you can do what C and C++ programmers have been doing for decades and pass some variables by reference into which you stick the return values.

function try_something($something, $somethingelse, &$return)
{
   if($something!=$somethingelse) // some sort of error occurred
        return false;

// Only runs if there's no error.
$return = "The return value";
return true;
}


//...

$bork = null;
$tried = try_something(42, 42, $bork);
if($tried) echo $bork;

Just a suggestion: right now I can't think of a situation where I actually did this in PHP.

[macleo]

use array