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Odd Issue with ^= operator in Java
By Tomg, history, 6 years ago, In English

In Java, why is it that the code a^=b^=a^=b does not swap the values of a and b, while in C++, such code works? For example if a=1, and b=5, in Java, after doing a^=b^=a^=b, a=0, b=1.

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6 years ago, hide # |
 
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This expression is expanded into a = a ^ (b = b ^ (a = a ^ b)); then the left-hand operand is evaluated first which results in the first a after = not getting "updated" after the innermost ^= as you are probably expecting.

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