The Parameters and their types table shows the parameters and parameter classes, if any, for events and actions. Using the table, you can define parameters to be sent with an event or action.

Parameters for events pass information when an event occurs. For example, suppose you assign a parameter to an event such as pushing a button that represents a key on a calculator. When the button is pressed, the button can pass the value of its label, say the number 5, as well as tell other parts that it has been selected.

Parameters for actions provide information necessary for a particular behavior. For example, suppose you use the add: action of an ordered collection. To use add:, you need to specify a parameter that contains the object being added to the collection.

To define parameters, select one of the following pop-up menu choices by clicking mouse button 2 over a row or column heading in the table:

After you add a row, you can type directly into the cells on the row by clicking on a cell using mouse button 1, and then typing text into the cell. You can move the editing cursor among the cells using the Tab and Backtab keys.

The parameters are passed in the order they occur in the table. For example, suppose the Action selectoraddTo:with:and: has the following parameters:
1. aCollection Collection
2. parm1 Object
3. parm2 Object

The parameters become arguments of the method in the following order:
addTo: aCollection with: parm1 and: parm2