Using bitwise operators to swap individual bits

Question

I'm able to set or clear individual bits using masks, however I'm trying to figure out how I could go about swapping two bits using bitwise operators but I haven't been able to figure it out. For example, say I had int x = 37 which is 100101 in binary and I wanted to swap the 2nd and 3rd bits I'd like to get 100011 when I use Integer.toBinaryString(x) after performing some bitwise operations on x to swap bits around. Any suggestions ?

Answer 1

How about something like this? A preliminary test seemed to work.
class BitSwap2 {
  public static void main(String[] argv) {
    int x = 37;
    System.out.printf("Binary: %s\n", Integer.toBinaryString(x));
    swapBits(x, 2, 3);
  private static void swapBits(int x, int a, int b) {
    if(a == b) {
      System.out.printf("Nothing to swap.\n");
      return;
    int first = (x & (1<<(a-1)));
    int second = (x & (1<<(b-1)));
    // zero them out from the original so that we can swap them
    x ^= (first | second);
    if(a > b) {
      int diff = (a - b);
      x |= (first >> diff);
      x |= (second << diff);
    } else {
      int diff = (b - a);
      x |= (second >> diff);
      x |= (second << diff);
    System.out.printf("Binary: %s\n", Integer.toBinaryString(x));
}