# <small>nlohmann::basic_json_document::</small>source

```cpp
view_type::string_view_t source() const noexcept;
```

Returns the parsed text, whether it is borrowed from the caller or owned by the document.

## Return value

A `#!cpp string_view_t` (`#!cpp std::string_view` on C++17 and newer) over the parsed text, or an empty one if the
document is [discarded](is_discarded.md).

## Exception safety

No-throw guarantee: this function never throws exceptions.

## Complexity

Constant.

## Notes

For a borrowed document, `source()` points directly into the caller's buffer, so it is only valid while that buffer
is; see [`owns_source`](owns_source.md).

The text of a document that owns it must not be passed to [`read()`](read.md) of the same document: `read()` releases
an owned text before it parses its input. Copy it first. (A borrowed text belongs to the caller and is not affected.)

## Examples

??? example

    ```cpp
    --8<-- "examples/basic_json_document__source.cpp"
    ```

    Output:

    ```json
    --8<-- "examples/basic_json_document__source.output"
    ```

## See also

- [`owns_source`](owns_source.md) - return whether the document holds its own copy of the text
- [`source_offset`](../basic_json_view/source_offset.md) - byte offset of a value in the source text
- [Zero-copy JSON views](../../features/json_view/lifetime.md) - who owns the source text and for how long

## Version history

- Added in version 3.13.0.