Source

SWAP VALUE

for example we have 2 uint variables, like:

• x = 10
• y = 15

---

• the binary representation of 10 is 1010
• and the binary representation of 15 is 1111

---

• x = x ^ y => 1010 ^ 1111 => 0101
• y = x ^ y => 0101 ^ 1111 => 1010
• y = (1010 ^ 1111) ^ 1111
• y = 1010 ^ (1111 ^ 1111)
• y = 1010 ^ 0
• since x ^ 0 = x
• y = 1010
• x = 0101 ^ 1010 => (1111 ^ 1010) ^ 1010 => 1111 ^ (1010 ^ 1010) => 1111 ^ 0 => 1111

NOW x = 15 AND y = 10 .

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Review

• SmartContract

function featureSwapValue(uint x, uint y) internal pure returns (uint, uint) {
    x = x ^ y;
    y = x ^ y;
    x = x ^ y;
    return (x,y);
}