### Check all
The `indeterminate` property can help you to achieve a **check all** effect.
```jsx live
() => {
const { Group } = Checkbox;
const Wrapper = () => {
const [checkboxVal, setCheckboxVal] = React.useState(['a', 'c']);
const [indeterminate, setIndeterminate] = React.useState(true);
const [checkAll, setCheckAll] = React.useState(false);
return (
<>
{
val ? setCheckboxVal(['a', 'b', 'c']) : setCheckboxVal([]);
setIndeterminate(false);
setCheckAll(val);
}}
checked={checkAll}
indeterminate={indeterminate}>
Check All
{
setCheckboxVal(val);
setCheckAll(val.length === 3);
setIndeterminate(val.length < 3 && val.length > 0);
}}>
A
B
C
);
};
return (
);
}
```