how throw exception if decimal value is bigger than float in C#

Question

i want throw exception if value of decimal is bigger than float (without floating point)

this sample code below works fine (throw overflowException) for integer

decimal a = decimal.MaxValue;
int b = checked(int.Parse(a.ToString()));

but this sample code does not throw any exception

decimal a = decimal.MaxValue;
float b = checked(float.Parse(a.ToString())); // b is 7.92281625E+28

how find out if value of decimal is bigger than float(without floating point)?

Answer 1

int b = checked(int.Parse(a.ToString()));

is a very bad way of checking whether a value will cause an OverflowException , because you don't know how a will be represented as a string.

Instead, use a cast :

decimal d = decimal.MaxValue;

int i = (int)d;
// Throws OverflowException

As @Enigmativity and @CodeCaster pointed out in the comments, the integer part of a decimal will always fit in a float :

decimal d = decimal.MaxValue;

float i = (float)d;
// No problem!

You can use decimal.Truncate if you just need to remove the fractional part of a decimal .