identifying integer assigned to double, how to?

[austinium]

hi,

This is part of a calculator, right now the input goes into a double value and the result is also a double value, so 2*2 ends up being 4.000..., which is correct but not very pretty. So i need to figure out a way to represent integer results as integers.

i need to know if the user entered an integer so that i can display the output as an integer without decimal followed by 0s. for instance the result of 2*2 should be displayed as 4 and not 4.000000...,

the code snippet fails if the value of the decimal part is 0000000000000001 for instance if i store 1.0000000000000001 into doublevar, the if condition fails, why? i dont know yet , i'll have to deal with this once i've figured out how to extract the integer value if the user has entered an integer into the double value.

how can i extract the integer value from the double variable if the user has entered an integer? sizeof(int) is 4 bytes, sizeof(double) is 8 bytes. i need to extract the integer and then check it for range -2147483648 to 2147483647. If i cast the double value to int explicitly is there any chance i'll lose data?

thanks again for the replies