I think the below program should atleast run once as the condition is true or maybe i am getting it wrong. Please enlighten me

Question

a very simple program but i can't figure out why it prints nothing. it should atleast run once.

int main()
{
float x = 1.1 ;
while ( x == 1.1 )
{
 printf ( "%f\n", x ) ;
 x = x-0.1 ;
}
return 0 ;
}

Answer 1

The decimal fraction 1.1 cannot be represented exactly using binary floating-point numbers (just like fraction 1/3 cannot be represented exactly using decimal floating-point numbers).

When you attempt to put 1.1 in type double, what you really store is 1.100000000000000088817841970012523233890533447265625

When you attempt to put 1.1 in type float, what you really store is 1.10000002384185791015625

Those values are not equal, so "x == 1.1" is false!

To make your program work, either use double

or use float:

````float x=1.1f; while (x==1.1f) ... 
but don’t mix the types