go - ^ 有什么作用？

Question

我希望这个问题不是太愚蠢...我不知道 ^ 运算符在 Go 中做了什么，例如

a := 3^500

起初我认为它一定是 pow 但它肯定不是。也不是 mod (%)。

我试过浏览文档并在 Google 上搜索，但不幸的是，Google 不认为 ^ 是搜索词。

Answer 1

与大多数语言一样，caret 运算符是按位异或。你可以在整数上使用它。

Relevant Golang documentation

Wikipedia on the bitwise xor :

A bitwise XOR takes two bit patterns of equal length and performs the logical exclusive OR operation on each pair of corresponding bits. The result in each position is 1 if only the first bit is 1 or only the second bit is 1, but will be 0 if both are 0 or both are 1. In this we perform the comparison of two bits, being 1 if the two bits are different, and 0 if they are the same

The bitwise XOR may be used to invert selected bits in a register (also called toggle or flip). Any bit may be toggled by XORing it with 1. For example, given the bit pattern 0010 (decimal 2) the second and fourth bits may be toggled by a bitwise XOR with a bit pattern containing 1 in the second and fourth positions:

     0010 (decimal 2)
 XOR 1010 (decimal 10)
   = 1000 (decimal 8)

This technique may be used to manipulate bit patterns representing sets of Boolean states.

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Also as a unary operator, it's bitwise not. e.g. ^uint(0) results in the uint value 0xffffffff for 32-bit machine and longer for a 64-bit machine.