Create a mathematical symbol in C#?

Unity Engine
1

Hi!

I’m looking for a way to dynamically define a mathematical sign. For example, let’s say I’m adding 2 numbers:

Answer = NumberOne + NumberTwo;

Now, if I want to switch the “+” to a “-”, I currently do this:

bool IsPlus;
IsPlus = true;
if(IsPlus)
    Answer = NumberOne + NumberTwo;
else
    Answer = NumberOne - NumberTwo;

To me, that looks pretty dumb. There’s got to be a smarter way to do this! I found Math.Sign, but that’s not what I’m looking for, that’s just to get the sign of a number.

2

Hi,

what about this;

var multiplier = IsPlus? 1 : -1;
Answer = NumberOne + multiplier * NumberTwo;

Note:
multiplier = IsPlus? 1 : -1;
is equal to
if(isPlus){
multiplier = 1;
}else{
multiplier = -1;
}

3

Not sure I understand exactly what you’re asking. But there’s not really anything wrong with doing code like what you show, assuming you have a function in which can either add or subtract.

There are probably ways to condence it a bit but it’d also make it less obvious what you’re doing so just keep it as is.

4

What’s the overall purpose? Do you need more operations? Who or what does influence the decision which operator to use?

You could outsource this into a helper method with a parameter which indicates the operation to execute, or abstract that all by using delegates or your own interface like ‘IBinaryOperation’.
Under certain conditions, you could assign a new delegate or a different implementation to the variable that holds an operation instance.

If it’s just about Plus and Minus, I’d just to do it the way you’ve already done it.

5

Thanks for the replies. This is currently what I’m doing:

transform.position = Vector3.Lerp(transform.position, new Vector3(Player.position.x + Offset.x, transform.position.y - DodgeDistance, Player.position.z + Offset.z), smooth);

And I often have to change the sign before DodgeDistance into a + or -. That’s why I was concerned with my method of handling that, but I guess there’s not much to improve.

6

I’d double check the code that sets DodgeDistance and see if it’s better to set the negative there, so later you can always add it.

bool IsPlus;
IsPlus = true;
if(!IsPlus)
    NumberTwo *= -1;
Answer = NumberOne + NumberTwo;