> For the complete documentation index, see [llms.txt](https://smllang.gitbook.io/home/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://smllang.gitbook.io/home/basics/structure-field-access.md).

# Structure field Access

The need for field access

Defining data structures is important for writing efficient and maintainable software. Without the ability to access and use the data stored structures become a redundant feature. In SMLL data structure fields can be extracted from instances either using [Object Destructuring](/home/basics/object-destructuring.md) or using the `::` operator. 

```rust
struct Foo (bar: Int)

fn main(): Unit => 
    let
        baz = Foo {bar: 200}
    in printf("Bar = %d\n", baz::bar) 
```

This allows the users to write concise code that that is re-usable as structs can be composed to form even more complex data structures.