doubt on comparision operator

Hi
the followiing code is giving 1 as answer but answer should be 0 ...becoz 0.7 is not grater than 0.7

Code:

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int main()
{
float a=0.7;
printf("%d",(0.7>a));
}

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please tell me the reason

It's due to the way the numbers are stored. 0.7 cannot be accurately stored, only approximated, with a float. However, when you compare it to the other 0.7, you're likely comparing a float (a) to a double (0.7). The double has more accuracy, and can store a value that is more accurate (and apperanly larger) than a.
If you change "float" to "double", your comparison will probably fail.

thanks for your information

Interesting...

http://cboard.cprogramming.com/showt...ight=float+0.7

http://cboard.cprogramming.com/showt...ight=float+0.7

You're all using the same constant.

Quote:

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Originally Posted by Cactus_Hugger

It's due to the way the numbers are stored. 0.7 cannot be accurately stored, only approximated, with a float. However, when you compare it to the other 0.7, you're likely comparing a float (a) to a double (0.7). The double has more accuracy, and can store a value that is more accurate (and apperanly larger) than a.
If you change "float" to "double", your comparison will probably fail.

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bad advice though to give to somebody who doesnt understand this yet. He now may think that using doubles prevents those bugs

Quote:

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Originally Posted by Cactus_Hugger

If you change "float" to "double", your comparison will probably fail.

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How about "most assuredly" instead of "probably?" Finite precision or not, the literal "0.7" will translate to the same double precision value in either context. Doubles are not infinitely precise; that doesn't mean they have some kind of quantum uncertainty ;)