将equals而不是equals传递给函数

Question

I have two sections of code A and B that are identical to each other, except that A has this

if(x == y)

and B has this

if(x != y)

where x and y are integers.

I want to reduce replication of code and so wanted to put this code in a separate method. The question is how do I pass the == and != operators into such a method and execute it?

Answer 1

Like xor it with a bool?

bool negate = true;
...
if ((x == y) ^ negate)
  ...

In case of integer equation and inequity it can solve your problems easily.

Answer 2

You can pass a Func<int, int, bool>

private void MyMethod(Func<int, int, bool> checker)
{
    if(checker(3, 4))
    {
         // Do Something.
    }
}

Answer 3

Maybe do like this:

void TheMethod(Func<int, int, bool> criterion)
{
  ...

  if (criterion(x, y))

  ...
}

then call with TheMethod((x, y) => x == y); or TheMethod((x, y) => x != y); .

Answer 4

You want to use a boolean function that acceps a flag for evaluating equality or inequality:

bool Eval(bool enforceEquality, T x, T y)
{
   if(enforceEqality)
      return x == y
   else 
      return x != y
}

The name Eval could use some work, but this way you pass the flag in from outside & use it to determine which evaluation returns true.