How to get most significant n bits from int in java

问题

I have an int, and I would like to get the 19 most significant bits in java. I tried all sorts of methods, none of them work. Can someone please help me?

回答1:

From the 32 bit int, you want to keep the 19 most significant, so discard the 13 least; then you shift right by 13 bits, but have to get rid of the possible sign extension, by anding with a 19 bit pattern:

(myint >> 13) & 0x7ffff

回答2:

Adding to Bram's answer, you don't even need the AND if you use unsigned shift.

myInt >>> 13; will give you the 19MSB (although they're now situated in the lowest bits).

回答3:

Integer is of 4 byte i.e. 4*8 = 32 bits. So if you want to get 19th bit, you may want to try something like:

 if (myint & 0X00002000 >> 19 == 1) {
     //do something
 }

来源：https://stackoverflow.com/questions/28876549/how-to-get-most-significant-n-bits-from-int-in-java