inputParser with only a value, not a name-value pair

Is it possible to use inputParser with only a value, not a name-value pair. So that when you send a function a specific argument, the argument is automatically set to a variable, without a variable name needed to be given in the function call?

As an example, taken from https://www.mathworks.com/help/matlab/ref/inputparser.html :

Instead of

a = findArea(13,'shape','square');

You could just send findArea 'square', like:

a = findArea(13,'square');

And within the function, it would recognize that square can only be a shape and set shape's value to 'square'.

Answer 1

[Fangjun Jiang]

Yes. You would make that a required argument, not an optional argument.

function a = findArea(width,Shape,varargin)

....

addRequired(p,'shape',defaultShape,... @(x) any(validatestring(x,expectedShapes)));

[Gregory Dachner]

I'm not sure what you expect this to do, but it breaks the function, causes all inputs to return the error:

Error using inputParser/addRequired Too many input arguments.

[Fangjun Jiang]

should be

   addRequired(p,'shape', @(x) any(validatestring(x,expectedShapes)));