A radio button is a small circular form control for choosing exactly one option from a group. Selecting one fills its circle and clears the previously selected option. section 8.3.6
Use radio buttons when the choices are mutually exclusive and the group is short:
- Offer choices such as Friday, Saturday, or Sunday for an event. section 8.3.6
- Offer a small set of shirt sizes, such as Small, Medium, Large, and Extra Large. section 8.3.6
- Prefer a selection list when there are more than about four choices, because many radio buttons can confuse users and consume page space. section 8.3.7
T-shirt size
Create a group labeled “Choose a t-shirt size” with Small, Medium, Large, and Extra Large options. Make Medium initially selected. A legend supplies the group caption, while the selected value is the choice submitted with the form. section 8.3.6 section 8.5.1
In submitted HTML forms, each radio button has a name identifying its field and a value identifying that option. The browser sends the value of the selected button; for example, a day field can submit Saturday. section 8.5.1
A group of radio buttons with the following options: "Small", "Medium", "Large", and "Extra Large". Include a legend element with the caption "Choose a t-shirt size".
Inspect a complete radio-button prompt with Small, Medium, Large, and Extra Large choices and the legend “Choose a t-shirt size.” section 8.3.6
