在一行中更改多个变量？

Question

Lets say I have this

int x = 0;
int y = 0;
int z = 0;
const int v = 50;

//change x,y,z
x += v;
y += v;
z += v;

Its fine, but is there a shorter way to avoid this 3 lines of code (with += ) and have only one? I just asking myself, because I have to add some const to these variables very often and then I have to add always +3 lines (or more if I would have xyz+ variables).

Answer 1

If this is going to happen very often, you might want to put these in a class. For example, if these are locations within a virtual page:

class PageLoc
{
    public int Header { get; set; }
    public int Body { get; set; }
    public int Footer { get; set; }

    void MoveAll(int distance) {
        Header += distance;
        Body += distance;
        Footer += distance;
    }
}

That way, you can change their values independently or collectively.

Answer 2

You could define a method to increment all three variables and pass the variables by reference:

Add(ref x, ref y, ref z, 50);

with

void Add(ref int x, ref int y, ref int z, int v)
{
    x += v;
    y += v;
    z += v;
}

Answer 3

Wrap the x,y,z into a class and write a method to add a constant to all three:

class XYZ
{
  public void Add (int v) { x += v; y += v; z += v; }
  int x,y,x;
}

Some code to use above:

void F ()
{
  XYZ xyz;

  xyz.Add (3);
}

Of course, you can improve the above by overloading the += operator as well as the other operators. In effect, you've created a vector and there's libraries available that already implement this (maybe in DirectX).

Answer 4

z += 0 * (y += 0 * (x += v) + v) + v;

Tadah :D

But I don't recommend using this! Of course the better way is to create a method that does that. That would also give you only one line (+ a method declaration).