HashCode.Combine 是可交换的吗？

Question

具体是

HashCode.Combine<T1,T2>(T1, T2)

交换？ IE。是真的吗

HashCode.Combine(a, b) == HashCode.Combine(b, a)

for any a and b?

Answer 1

为什么不进行一个简单的实验，例如

public static void Experiment() {
  for (int i = 0; i < 100; ++i)
    for (int j = 0; j < 100; ++j) {
      int a = HashCode.Combine(i, j);
      int b = HashCode.Combine(j, i);

      if (a != b) {
        Console.Write($"Combine({i}, {j}) = {a} != {b} = Combine({j}, {i})");

        return; 
      }
  }

  Console.Write("Seems to be commutative");  
}

结果：

Combine(0, 1) = -839320321 != 864340100 = Combine(1, 0)

所以Hash.Combine（当前实现，.Net Core 3.1）不是可交换的

HashCode.Combine 是可交换的吗？

Is HashCode.Combine commutative?

c#

hashcode