Tony and Nain
It think what the question is asking is which ones can effect the sign of the left hand side. However, I think it could have been worded better because Sun uses the
word 'signed' in the actual name of the operator. From the
JLS section 15.19:
'The shift operators include left shift <<, signed right shift >>, and unsigned right shift >>>'.
What they are refering to is the treatment of the sign of the original value. In the signed right shift >> the operator ensures that the sign of the left hand side remains the same. In the other two it takes no special note of the sign and basically lets whatever happens happen.
hope that helps
------------------
Dave
Sun Certified Programmer for the Java� 2 Platform