How can I override a value with an input?

I have a list of variables with values, but I want to be able to override one of those values with an input. To demonstrate:

function [output] = test(variable, value)
  x = 2;
  y = 3;
  q = 10;
end

And let's say my input is (x, 5). Other than using a bunch of if statements, is there a way to make x = 5?

[Azzi Abdelmalek]

This is not clear, variable and value are not used in your function

[Andrew]

That's the thing, I don't know how to use them. 'variable' should match one of the ones declared in the code (i.e. x, y, or q) and 'value' is whatever value that variable should be. So if my input is (y, 10), then I want to set y = 10.

I'm explaining this poorly, I apologize, but I'm not quite sure how else to describe it.

Answer 1

[A Jenkins]

Some of it depends on how much you want to protect against "bad" values or variable names being passed. But here is a simple trick:

function [output] = test(variable, value)
  mydata.x = 2;
  mydata.y = 3;
  mydata.q = 10;
  mydata.(variable)=value
end

........................................................

>> test('x',5)

mydata = 

    x: 5
    y: 3
    q: 10

[Andrew]

Yeah, that should work, thanks!

Answer 2

[Geoff Hayes]

Could also just compare the input variable to a set of pre-defined "matches"

 function [output] = test(variable, value)

x = 2;
y = 3;
q = 10;

if ischar(variable) && isvector(variable)
    if strcmp(variable,'x')
        x = value;
    elseif strcmp(variable,'y')
        y = value;
    elseif strcmp(variable,'q')
        q = value;
    end
end

The above will guard against the case where variable is not a string, and is one of x, y, and q.