2.00 ISNT == to 2.00 and I've no idea why.... 1

[Sedai]

i have double variable that is assigned the value of a function.
I cerr the variable with 20 precision and it gives
2.000000000000... then I compare it with another variable that is equal to 2.00 and the if statement x==y doesnt execute. insted the else statement executes.
just to test, in the else statemnt I put cerr << x << &quot; &quot;<< y;
and it gives 2.00000 2.00000

what could be the problem.
it executes the statment if x<2.00

please help. that's truly STRANGE.
probably it's something simple but I don't get it.
thank you. Avendeval

 

[fheyn]

comparing double-type variables for equality is highly
doubtful. this works correctly with ints or chars.
if I have to compare that way, I usually define a variable
ZERO which is 0.000001. then I calculate the difference
between variable a and b and with abs() I make sure the
result is positive. that result I will compare with ZERO for LESS.
try it out that way.

 

[Sedai]

THANKS! Avendeval