CODEWITHSUNDEEP
c#hex
nullable
nullable

Reputation: 2581

Converting float to hex format

Given the following variable:

float myFloat = 0xC0451EB8;

How do I get C0451EB8 from myFloat?

Edit: Not sure why I am being down voted here with no comment. I am not asking a simple hex representation of a float or uint32. I can do this. Given the variable definition above and a [possible common] answer of:

string FloatAsHex(float myFloat) {
  return BitConverter.ToString(BitConverter.GetBytes(myFloat));
}

FloatToHex(0xC0451EB8); //will output 1F-45-40-4F, not what I expect
FloatToHex(BitConverter.ToSingle(BitConverter.GetBytes(0xC0451EB8))) //works

Although the second one obviously works, I only have access to the float variable.

Upvotes: 1

Views: 4500

Answers (2)

Peter Duniho
Peter Duniho

Reputation: 70691

There is no way to accomplish what you're asking. Your code is storing the integer value 0xC0451EB8, or in decimal 3225755320, in a variable of type float. The integer value has 32 bits of precision, but a float cannot represent 32 bits of numeric precision, because some of the 32 bits of the float value are committed to the exponent.

Thus, the integer value 3225755320 gets truncated to 3225755392.

You can cast the float back to uint, and then use the standard mechanism for formatting as a hexadecimal string value. E.g. ((uint)myFloat).ToString("X"). But when you do that, you'll be starting with the truncated value, and the output will be "C0451F00" (or "0xC0451F00" if you include the standard hex specifier prefix in your format string).

Once you truncate the original value, there is no way to recover it. You cannot reverse the process.

Upvotes: 1

Uriel Zilberberg
Uriel Zilberberg

Reputation: 119

The documentation says to use BitConverter.ToString Method (Byte[]) on msdn

This will return a string representation of the number in hex base. Example (for array of bytes representing a number):

00-01-02-04-08-10-20-40-80-FF

Upvotes: 0

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