The again, in PHP, interpreting strings as floats is not unusual and pretty well defined. So in PHP it's also a case the developer could have considered normal in his expectation that PHP would behave as usual (and it did, prior to 5.3, for this precise function)

Not for user-provided input. That's just a dumb thing to do in any language.

Probably. But then again, we're talking about a language where THIS happens:

php> echo "2coolforschool" + 1;

3

php> echo "2.1coolforschool" + 1;

3.1

php> echo "coolforschool" + 1;

1

So treating all kinds of garbage as valid numbers is absolutely part of PHP.

That's just the general design philosophy of the MP components of the LAMP stack.

Do the stupidest thing that could possibly work; and it probably will. For now.

> Not for user-provided input.

Not what for user-provided input? The source of a string does not matter to this rule of PHP: a string used in numeric context will be parsed and converted, if it can not be parsed as a number its numeric value will be 0. That's it. That's how the language defines strings in numeric contexts.

> That's just a dumb thing to do in any language.

Sure, you won't get any argument from me on that, but that remains how PHP works and has always worked.