a stupid question - Externals

17 years ago by Ting Chen — view source — reply

unread

Hi everybody,

sorry this is a greenhand's stupid question. Why isn't "0.0" false? I
know it is a string but I still think it equals to 0.

Thanks ahead, green green~~

17 years ago by Andrew Rose — view source — reply

unread

2008/11/17 Ting Chen gilltdr1008@gmail.com:

Hi everybody,

sorry this is a greenhand's stupid question. Why isn't "0.0" false? I
know it is a string but I still think it equals to 0.

I think you answered your own question there.

Andrew

17 years ago by Ting Chen — view source — reply

unread

i am recently studying Php5 manul. This is one of the examinations in
the book. The answer is "0.0" is true rather than false. I am very
curious about why if the answer is not wrong.

green geen still green~

2008/11/17 Ting Chen gilltdr1008@gmail.com:

Hi everybody,

sorry this is a greenhand's stupid question. Why isn't "0.0" false? I
know it is a string but I still think it equals to 0.

I think you answered your own question there.

Andrew

17 years ago by Igor Feghali — view source — reply

unread

maybe because "0" evaluating to false is already enough and everything
after that would be "forcing" too much. If "0.0" evaluates to false
then I would ask, why "0.0E1" doesn't ? What about "0.0E2" ? "0.0E10"
? etc. Just my opinion.

regards,
Igor.

i am recently studying Php5 manul. This is one of the examinations in
the book. The answer is "0.0" is true rather than false. I am very
curious about why if the answer is not wrong.

17 years ago by Ting Chen — view source — reply

unread

thanks for answering my question,

green, green, I am so green

maybe because "0" evaluating to false is already enough and everything
after that would be "forcing" too much. If "0.0" evaluates to false
then I would ask, why "0.0E1" doesn't ? What about "0.0E2" ? "0.0E10"
? etc. Just my opinion.

regards,

Igor.

i am recently studying Php5 manul. This is one of the examinations in
the book. The answer is "0.0" is true rather than false. I am very
curious about why if the answer is not wrong.

17 years ago by Federico Lebron — view source — reply

unread

Andrew Rose wrote:

2008/11/17 Ting Chen gilltdr1008@gmail.com:

Hi everybody,

sorry this is a greenhand's stupid question. Why isn't "0.0" false? I
know it is a string but I still think it equals to 0.

I think you answered your own question there.

Andrew

What he means is that == is not transitive. That is,

"0" == false
"0" == "0.0"
But
false != "0.0"

The answer to "why" is, well, that's the way it is. "0.0" just "looks"
too much like a string, maybe, to be made into a boolean. You can just
cast it into int like (int) "0.0" to make it work, however.

Federico Lebron