java - Finding a specific nibble in an integer -


how go finding nibble in integer using bitwise operations?

i need extract given nibble, specifically.

the method looks this

private int nibbleextract(int x, int whichnibbletoget)

and example on method return

nibbleextract(0xff254545, 7); // => 0xf

you can shifting number 4 times nibble index, , masking 0xf:

int nibbleindex = 7; int data = 0xff254545; int nibble = (data >> 4*nibbleindex) & 0xf;

how without multiplication?

like this:

int nibble = (data >> (nibbleindex << 2)) & 0xf;

modern optimizers convert 4*x x << 2 you, 2 alternatives turn out give same performance (while first 1 of course more readable).


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