shift

[josephine chen]

The following code will print
1: int i = 1;
2: i <<= 31; 1*2^31 = 2^31<br /> 3: i >>= 31; 2^31 /2^31 = 1
4: i >>= 1; 1>>=1 1/2 === 0
5:
6: int j = 1;
7: j <<= 31; 1*2^31<br /> 8: j >>= 31; 2^31/2^31 ==1
9:
10: System.out.println("i = " +i );
11: System.out.println("j = " +j);
A) i = 1
j = 1
B) i = -1
j = 1

C) i = 1
j = -1//answer how come???

D) i = -1
j = -1

[josephine chen]

where am i going wrong

[Jim Yingst]

For a problem like this, it's useful to print out intermediate results so that you can see for yourself if you're on the right track:

  int i = 1;
  i <<= 31; // 1*2^31 = 2^31
  System.out.println("A: i = " + i);
  i >>= 31; // 2^31 /2^31 = 1
  System.out.println("B: i = " + i);
  i >>= 1;  // 1>>=1 1/2 === 0
  System.out.println("C: i = " + i);
  int j = 1;
  System.out.println("A: j = " + j);
  j <<= 31; // 1*2^31
  System.out.println("B: j = " + j);
  j >>= 31; // 2^31/2^31 ==1
  System.out.println("C: j = " + j);

[This message has been edited by Jim Yingst (edited February 22, 2000).]

[Jane Rozen]

For those who search for "shift" on this forum - make sure you follow Jim's advice - check the result!
Hint:it will be D) i=-1, j=-1 .