Bitwise Operator ( ) help

Question

I'm a new beginner and I have some problems with such code:
class Test {
     public static void main(String[] args) {
          int i = -1;
          int a = i;
          for ( int k = 0 ; k < 32 ; k ++ ) {
               i = i >>> 1;
               System.out.print(i+" ");
               System.out.println(a >>> (k+1) );
I hope that the two columns of the output wil be the same, but the
last line isn't.
Why a == -1 after " int a = -1; a = a >>> 32 " ? I think a should be 0.
Am I right or is there any mistake?

Answer 1

See the language spec:
http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#5121
in particular:
If the promoted type of the left-hand operand is int, only the five lowest-order bits of the right-hand operand are used as the shift distance. It is as if the right-hand operand were subjected to a bitwise logical AND operator & (�15.22.1) with the mask value 0x1f. The shift distance actually used is therefore always in the range 0 to 31, inclusive.
Though it doesn't say why.