json/api/json_view.md

nlohmann::json_view

Defined in header <nlohmann/json_view.hpp>

using json_view = basic_json_view<json>;

This type is a basic_json_view of a value of a json_document.

Examples

??? example

The example below demonstrates how to use the type `nlohmann::json_view`.

```cpp
#include <iostream>
#include <nlohmann/json_view.hpp>

int main()
{
    std::cout << std::boolalpha;

    // json_view is basic_json_view<nlohmann::json>: a read-only handle
    // returned by json_document::root()
    nlohmann::json_document doc = nlohmann::json_document::parse("[1, 2, 3]");
    nlohmann::json_view v = doc.root();

    std::cout << v.is_array() << ' ' << v.size() << '\n';
}

```

Output:

```json
true 3

```

See also

• json_document - the document type this view refers into
• ordered_json_view - the corresponding view for ordered_json_document

Version history

Since version 3.13.0.