---
category: Components
type: Form Controls
title: Radio
---

Radio.

## When to use

- Used to select a single state in multiple options.
- The different between Select, Radio is visbile to user, it can facilitate users in the comparison of choice. So, when you want to use Radio, option should not be too much.


## API

### Radio

| Property           | Description                                     | Type       |  optional | Default |
|----------------|------------------------------------------|------------|---------|--------|
| checked | Specifies whether the radio is selected. | Boolean | false |
| defaultChecked | Specifies the initial state: whether or not the radio is selected. | Boolean | false |
| value          | According to value for comparison, to determine whether the selected        | String     |         | none     |

### RadioGroup

radio group，wrap a group of `Radio`。

| Property           | Description                             | Type              | optional | Default |
|----------------|----------------------------------|-------------------|--------|--------|
| onChange | The callback function that is triggered when the state changes. | Function(e:Event) | none     | none     |
| value | Used for setting the currently selected value. | String            | none     | none     |
| defaultValue   | Default selected value                     | String            | none     | none     |
| size           | Size, only on radio style           | String            | `large` `default` `small` | `default` |