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In Java a bitwise operation causes type casting to integer and also causes sign extension. For instance the following is expected:

byte b = -1;
System.out.println(b >> 1);//-1

In Java chars are encoded in UTF-16 and each unit is represented with 2 bytes. 

char c = 0xFFFF; //I assume now the sign bit is 1.
System.out.println(c >> 1);//32767 ???? WHY

I was expecting -1 instead of 32767. Why is the sign not extended during the type cast before the bitwise operation is applied? Any ideas?

CEGRD
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2 Answers2

12

Because char is unsigned - 0xFFFF really has a value of 65535

Michael Borgwardt
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3

It works like that because of widening primitive conversion that is performed on shift arguments. Namely there's no information loss, including the sign of the type being converted.

soulcheck
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