java negative binary literal

Asked Oct 19 '22 at 18:52

Active Oct 19 '22 at 19:08

Viewed 49 times

So to convert a positive binary number into a negative one I have to invert all of the bits of the number and add 1.

   `byte x = 0b0111_1111;
    System.out.println(x); // 127
    
    x = 0b1111_1111_1111_1111_1111_1111_1000_0001;
    System.out.println(x); // -127

I don't understand why I have to expand my number to 32 bit form by adding zeros on the left side before reversing the bits, why exactly to 32 bit form?

edited Oct 19 '22 at 18:53

Chris

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asked Oct 19 '22 at 18:52

wydra__

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You don't, you can write `x = (byte)0b1000_0001;`. – Progman Oct 19 '22 at 18:56
Also check other questions like https://stackoverflow.com/questions/8860948/how-to-specify-a-constant-is-a-byte-or-short – Progman Oct 19 '22 at 18:58
Because the binary literal is of type `int`, which is 4 bytes, which is 32 bits. – Andy Thomas Oct 19 '22 at 19:13

java negative binary literal

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