When you create a radio group, you associate a specific data value with each radio button in the group. When an end user selects a radio button, the value of the radio group changes to the value that you associated with the selected button.
For example, consider a radio group with three radio buttons that allows end users to specify which of three warehouses should fill an order. The radio button labels are New York, Chicago, and San Francisco.
The values associated with each radio button are numeric warehouse IDs:
Label |
Associated Value |
---|---|
New York |
100 |
Chicago |
200 |
San Francisco |
300 |
Selecting the radio button labeled New York sets the value of the radio group to 100 (the warehouse ID). When the end user commits the order, the value 100 is inserted in the corresponding database column. Similarly, when a value is fetched or assigned to the radio group, the radio button whose value matches the fetched value becomes the selected button in the group.
A radio group can store a fetched or assigned value that is not one of the values that you associated with a specific radio button in the group. When you create a radio group, you must specify how you want it to handle such Other Values. You can do so in one of two ways:
In the preceding example, you could specify that the radio button labeled "New York" be the currently selected button whenever an Other Value is fetched or assigned to the radio group. In this instance, the fetched value 149 would be an Other Value, and the radio button labeled "New York" would become the currently selected button.
Note that when an Other Value is fetched or assigned to a radio group, the designated radio button becomes the currently selected button, but the value of the item remains the Other Value until a new value is fetched or assigned, or until the end user selects a different button.
About radio group initial values
About defining check boxes, radio groups, and List items for querying