32-bit of precision, what does it mean?

Question

I'm reading a book about OPENGL ES development. I came across to this sentence.

A float in Java has 32 bits of precision, while a byte has 8 bits of precision. This might seem like an obvious point to make, but there are 4 bytes in every float.

What exactly does that mean? Is this important to know in Android game development?

Answer 1

What exactly does that mean?

1 Byte= 8 Bit

4 Byte= 32 Bit

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1Bit can have 2 conditions 0 or 1

2Bits can have 2² conditions 00 , 01, 10 and 11

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Ok, now it comes to the hard point

If your accuracy should be +/-0.5 *the maximum size* that your number can be is 2^23. Now you may ask yourself and what is if i got a number that is larger than this? Anything that is bigger than this is bigger than 0.5.

(Single-Precission /32 Bit)

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Is this important to know in android game development?

It is important, that you understood the basic concept behind this in nearly any programming language.

Take a look at that simple program, if you understood the output, that is all you need to know, first of all

public class DoubleError
{
       public static void main(String[] args)
       {
             double x = 1.1;
             double y = 0.1;
             System.out.println("X is: " + x);
             System.out.println("Y is: " + y);
             System.out.println("X+Y is: " + (x + y));

       }
}

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EDIT:

Oh, and to totally crash your head,

here some more points that you should know:

Half- Precision = 16 Bit

Single-Precision = 32 Bit

Double-Precision = 64 Bit

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EDIT 2:

Oh, and if you want to understand anything, check out this: IEEE_754-2008