C Function to Convert float to byte array

Question

I\'m trying to make a function that will accept a float variable and convert it into a byte array. I found a snippet of code that works, but would like to reuse it in a func

Answer 1

Here's a way to do what you want that won't break if you're on a system with a different endianness from the one you're on now:

byte* floatToByteArray(float f) {
    byte* ret = malloc(4 * sizeof(byte));
    unsigned int asInt = *((int*)&f);

    int i;
    for (i = 0; i < 4; i++) {
        ret[i] = (asInt >> 8 * i) & 0xFF;
    }

    return ret;
}

You can see it in action here: http://ideone.com/umY1bB

The issue with the above answers is that they rely on the underlying representation of floats: C makes no guarantee that the most significant byte will be "first" in memory. The standard allows the underlying system to implement floats however it feels like -- so if you test your code on a system with a particular kind of endianness (byte order for numeric types in memory), it will stop working depending on the kind of processor you're running it on.

That's a really nasty, hard-to-fix bug and you should avoid it if at all possible.