```
SELECT version()
─version()─┐
│ 21.8.5.7  │
└───────────┘
```
We have a request, as a result of which we get an array.
When getting an item using a computed value, there is no value
```
SELECT
    arrayMap(x -> x, [[1], [2], [3]]) AS x,
    toTypeName(x),
    x[3 - 2] AS y,
    x[toInt64(1)] AS yy,
    x[toUInt8(1)] AS yyy

┌─x─────────────┬─toTypeName(arrayMap(lambda(tuple(x), x), [[1], [2], [3]]))─┬─y──┬─yy─┬─yyy─┐
│ [[1],[2],[3]] │ Array(Array(UInt8))                                        │ [] │ [] │ [1] │
└───────────────┴────────────────────────────────────────────────────────────┴────┴────┴─────┘
```
However, when the array is explicitly specified, the value is present.
The types are the same.
```
SELECT
    [[1], [2], [3]] AS x,
    toTypeName(x),
    x[3 - 2] AS y,
    x[toInt64(1)] AS yy,
    x[toInt8(1)] AS yyy

┌─x─────────────┬─toTypeName([[1], [2], [3]])─┬─y───┬─yy──┬─yyy─┐
│ [[1],[2],[3]] │ Array(Array(UInt8))         │ [1] │ [1] │ [1] │
└───────────────┴─────────────────────────────┴─────┴─────┴─────┘
```


const ColumnsWithTypeAndName & arguments, const PaddedPODArray<IndexType> & indices, ArrayImpl::NullMapBuilder & builder)
{
    const ColumnArray * col_array = checkAndGetColumn<ColumnArray>(arguments[0].column.get());
    if (!col_array)
        return nullptr;
    const auto & col_nested = col_array->getData();
    auto col_res = col_nested.cloneEmpty();
    ArrayElementGenericImpl::vector<IndexType>(
        col_nested, col_array->getOffsets(), indices, *col_res, builder);
    return col_res;
}
template <typename IndexType>
ColumnPtr FunctionArrayElement::executeConst(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type,
                                        const PaddedPODArray <IndexType> & indices, ArrayImpl::NullMapBuilder & builder,
                                        size_t input_rows_count)
{
    const ColumnArray * col_array = checkAndGetColumnConstData<ColumnArray>(arguments[0].column.get());
    if (!col_array)
        return nullptr;
    auto res = result_type->createColumn();
    size_t rows = input_rows_count;