How can we swap two numbers without third variable and without arithmetic operator?

Question

One possible duplicate: http://stackoverflow.com/questions/756750/swap-the-values-of-two-variables-without-using-third-variable — Florin, Oct 14 '10 at 13:12
Another possible duplicate: http://stackoverflow.com/questions/1826159/swapping-two-variable-value-without-using-3rd-variable — Florin, Oct 14 '10 at 13:13

Florian Mayer · Accepted Answer · 2010-10-15T18:06:46.650

9

Does XOR count as an arithmetic Operator? If not, then:

X := X XOR Y
Y := X XOR Y
X := X XOR Y

Converting this pseudo-code to Java code that compiles is left as an exercise to the reader (with regards to the ‘java’ tag).

edited Oct 15 '10 at 18:06

answered Oct 14 '10 at 13:11

Florian Mayer

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1

If I remember correctly, though, this won't work if one of the values you're trying to swap is 0. – Anthony Oct 14 '10 at 13:13
And no, a value of zero is no problem at all. – Florian Mayer Oct 14 '10 at 13:22
Funny, I always thought that XOR was arithmetic, but at least it isn't the +, -, *, or / operators the poster is probably thinking about. – Edwin Buck Oct 14 '10 at 14:06
@Edwin, @Florian: XOR is a bitwise operator, so this fits the given requirements. @Shynthriir: 0 is fine, but it *is* a problem if X and Y refer to the same location in memory. – Michael Madsen Oct 14 '10 at 14:41

score 1 · Answer 2 · answered May 21 '18 at 15:43

private static void swap() {
    int a = 5;
    int b = 6;
    System.out.println("Before Swaping: a = " + a + " and b= " + b);
    // swapping value of two numbers without using temp variable and XOR bitwise operator
    a = a ^ b; // now a is 3 and b is 6
    b = a ^ b; // now a is 3 but b is 5 (original value of a)
    a = a ^ b; // now a is 6 and b is 5, numbers are swapped
    System.out.println("After  Swaping: a = " + a + " and b= " + b);

}

Output :

Before Swaping: a = 5 and b= 6
After  Swaping: a = 6 and b= 5

score 1 · Answer 3 · answered May 05 '19 at 14:42

public class SwapNumbers {

 public static void main(String[] args) {

  int x = 11;
  int y = 22;

  System.out.println("Before Swapping");
  System.out.println("Value of x is :" + x);
  System.out.println("Value of y is :" + y);

  x = x + y;
  y = x - y;
  x = x - y;

  System.out.println("Before Swapping");
  System.out.println("Value of x is :" + x);
  System.out.println("Value of y is :" + y);
 }
}

score -1 · Answer 4 · answered Apr 06 '17 at 08:09

class Swap{

 int a;
 int b; 

 public static void main(String args[]){
    a = 10;
    b =20;
    System.out.println("******Before Swap*********");
    System.out.println("a= "+a);
    System.out.println("b= "+b);
    a = a + b;
    b = a - b;
    a = a - b;
    System.out.println("******After Swap*********");
    System.out.println("a= "+a);
    System.out.println("b= "+b);
 } 
}

Your Output will be :

******Before Swap*********
a= 10
b= 20
******After Swap*********
a= 20
b= 10

Saiful · Answer 5 · 2018-07-10T12:39:03.637

-4

Using this ::

X = X ^ Y;
Y = X ^ Y;
X = X ^ Y;
*** ^ means XOR operation

edited Jul 10 '18 at 12:39

answered Jan 11 '12 at 07:03

Saiful

1,891
1
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But + and - are arithmetic operators which is exactly what you're not allowed to use. – Dan Jan 11 '12 at 08:05
2

Ok. check this http://stackoverflow.com/questions/756750/swap-the-values-of-two-variables-without-using-third-variable. – Saiful Jan 11 '12 at 08:33
Rolled back the inappropriate edit which just changed this answer into the other one. – Erick Robertson Jan 13 '14 at 14:36

How can we swap two numbers without third variable and without arithmetic operator?

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