Ignore Inputs in Function Definitions

This example shows how to ignore inputs in your function definition using the tilde (~) operator. Use this operator when your function must accept a predefined set of inputs, but your function does not use all of the inputs. Common applications include defining callback functions.

In a file namedcolorButton.m, define a callback for a push button that does not use theeventdatainput. Add a tilde to the input argument list so that the function ignoreseventdata.

functioncolorButton figure; uicontrol('Style','pushbutton','String','Click me','Callback',@btnCallback)functionbtnCallback(h,~) set(h,'BackgroundColor',rand(3,1))

The function declaration forbtnCallbackis effectively the same as the following:

functionbtnCallback(h,eventdata)

However, using the tilde prevents the addition ofeventdatato the function workspace and makes it clearer that the function does not useeventdata.

You can ignore any number of inputs in your function definition, in any position in the argument list. Separate consecutive tildes with a comma. For example:

functionmyFunction(myInput,~,~)

Ignore Inputs in Function Definitions

Related Topics