@yxcoder #5

``` typescript
function dosomething<K extends keyof TypeProp>(data: K): TypeProp[K];

function dosomething<K extends keyof TypeProp>(
data: K[],
): { [P in K]: TypeProp[P] }[];

function dosomething<K extends keyof TypeProp>(
data: K | K[],
): TypeProp[K] | TypeProp[K][] {
if (Array.isArray(data)) {
return data.map((key) => data1[key]);
} else {
return data1[data];
}
}
```