Question

i'm attaching a C pgm file here. I couldn't get the reason for output.

#include #include void main() { float f=0.7; if(f<0.7) printf("\n hi"); else printf("\n bi"); getch(); }

Answer 1

and what is the output?

Answer 2

try pasting the code at a site like http://codepad.org

Answer 3

Ahh it prints "hi".

Well, it's all about IEEE 754: http://www.parashift.com/c++-faq-lite/newbie.html#faq-29.17

Answer 4

u should use code editors like codepad and ideone

Answer 5

Specifically, in this example, you are comparing an object of type float to a double, which won't give you the expected false value.

Answer 6

To solve this, add the 'f' qualifier to the number 0.7, writing it as 0.7f

Answer 7

http://codepad.org/tsbI2gr9

Answer 8

would it work if you defined double f =0.7?

Answer 9

try it out!

http://codepad.org/B2lMqdUV

Answer 10

you probably always want to use double since it's more precise than float

Answer 11

Right; double is safest if you aren't sure.

Answer 12

and when float is better to use?

Answer 13

Here's the long answer: http://docs.oracle.com/cd/E19422-01/819-3693/ncg_goldberg.html

Answer 14

Short answer: it might depend on certain arithmetic you're trying to do, compiler implementation, machine implementation, FPU etc.

Answer 15

thanks i got it

Answer 16

the safest is variant