prototyping - Can someone tell me what Strong typing and weak typing means and which one is better?

Question

Can someone tell me what Strong typing and weak typing means and which one is better?

Answer 1

That'll be the theory answers taken care of, but the practice side seems to have been neglected...

Strong-typing means that you can't use one type of variable where another is expected (or have restrictions to doing so). Weak-typing means you can mix different types. In PHP for example, you can mix numbers and strings and PHP won't complain because it is a weakly-typed language.

$message = "You are visitor number ".$count;

If it was strongly typed, you'd have to convert $count from an integer to a string, usually with either with casting:

$message = "you are visitor number ".(string)$count;

...or a function:

$message = "you are visitor number ".strval($count);

As for which is better, that's subjective. Advocates of strong-typing will tell you that it will help you to avoid some bugs and/or errors and help communicate the purpose of a variable etc. They'll also tell you that advocates of weak-typing will call strong-typing "unnecessary language fluff that is rendered pointless by common sense", or something similar. As a card-carrying member of the weak-typing group, I'd have to say that they've got my number... but I have theirs too, and I can put it in a string :)