Invalid parameter error

Derokorian

I've been writing some functions lately and ever since brad told me about type hinting I've been using that to simplify how many checks I need on parameters. However since I can't type hint integer, float, string I am still checking those. What I'm trying to figure out it how to get my errors to match the ones PHP throws.

Catchable fatal error: Argument 2 passed to Database::insert() must be an array, string given, called in /database.class.php on line 79 and defined in /database.class.php on line 15

Is there an easier way to do this than check for each type that it could be (IE instead of doing is_string is_array is_object etc). And also if its possible to make it a Catchable fatal error. I can't seem to find what I"m looking for on google, so I'm hoping someone here can point me in the right direction.

Thanks in advance.

NogDog

You could throw an exception:

furnction foo($bar)
{
   if(!is_int($bar)) {
      throw new Exception("Invalid parameter, must be an integer");
   }
   // rest of function...
}

Derokorian

You're missing the point Nog... the point is I want it to say what it WAS passed as well, and I don't want to do this in every funciton:

function foo($bar) 
{ 
   if(!is_int($bar))
	{ 
		if( is_string($bar) ) 
			throw new Exception("Invalid parameter, must be an integer, passed a string");
		if( is_object($bar) )
			throw new Exception("Invalid parameter, must be an integer, passed an object of type ". get_class($bar) );
		// etc
   } 
   // rest of function... 
}

The other part that's missing, is the type of error AND the info (where it was called, and where it was defined)

Derokorian

I just wish I could do function foo(int $bar,str $str,mysqli $db,array $data) {} LoL

NogDog

[man]gettype/man

I just wish I could do function foo(int $bar,str $str,mysqli $db,array $data) {} LoL

Use a strongly typed language instead of using PHP. :p

Derokorian

never seen gettype before! Thanks =D

And like what language? I only have worked with html, css, php, and basic, little bit of java back in the day but I never really got into it (I think OOP was just OOver my head back then)

NogDog

Among languages commonly used for web development, probably Java, C#, or Python would be the most commonly used strongly typed languages. (I plan to get into Python over the coming year, though I've never really had an issue with PHP's loose typing -- maybe just because I don't know any better. 😉 )

Weedpacket

Well; it's not so much a difference between strong and weak typing, as between static and dynamic typing.

Statically-typed languages like Java or C# won't allow you to store an integer value in a string variable, while dynamically-typed languages like PHP or Python will.

The strong/weak difference is that the former will choke if you try and use an integer in a string context (e.g., Python will throw a TypeError exception), while the latter will try and cope (e.g., PHP will do the cast). So in a dynamically typed language, you're still left with the job of checking types at run time.

But how much of that type checking do you really need? If you have a function foo($i) that accepts an integer, do you want to forbid calling foo('42')?

If I do need type-validation (or type-coercion), I give the class in question a suitable set of methods that return void on success or throw an exception on error. Only public methods need protection like that, of course, and they tend to reduce to a set of validation checks followed by a call to the real method. It's also here that I mimic function overloading (though function overloading could be regarded as mimicking dynamic typing)...

jocelyndong

thanks very much for your suggestions, i will pay attention to.Lhasa Tibet