C＃中的pred和succ等价于什么？

Question

Pascal is my study language and I am curious whether C# also has the functions pred and succ .

This is what I have done in Pascal that I want to try in C#

// in Pascal:
pred(3) = 2
succ(False) = True
pred('b') = 'a'
type enum = (foo, bar, baz);
succ(bar) = baz; pred(bar) = foo

Is the same code applicable for C#, too? If so, what is the namespace for these functions?

(I searched Google, but couldn't find the answer)

Answer 1

There aren't pred and succ functions in C#. You just write n - 1 or n + 1 .

Answer 2

You can use ++ or -- operator:

3++ = 4
3-- = 2

Not sure why you would need it though when you can just do 3+1 or 3-1 :)

Answer 3

You have method overloading in c# so it's easy to have pred and succ, You can do it by:

public int pred(int input)
{
   return input - 1;
}

public char pred(char input)
{
  return (char)((int)input - 1);
}
....

Answer 4

Using extensions:

public static int Pred(this int self) => self - 1;
public static int Succ(this int self) => self + 1;

Then, this would work:

3.Pred() //-> 2
int x = 3;
x.Succ() //-> 4

Probably not considered very idiomatic, but still works. Would have to override for other integer types (like short ). Check if the calls get inlined if you're concerned with performance.

Note: ++ and -- act as Inc and Dec , not Succ and Pred .