1# basic_json::is_structured 2 3```cpp 4constexpr bool is_structured() const noexcept; 5``` 6 7This function returns `#!cpp true` if and only if the JSON type is structured (array or object). 8 9## Return value 10 11`#!cpp true` if type is structured (array or object), `#!cpp false` otherwise. 12 13## Exception safety 14 15No-throw guarantee: this member function never throws exceptions. 16 17## Complexity 18 19Constant. 20 21## Notes 22 23The term *structured* stems from [RFC 8259](https://tools.ietf.org/html/rfc8259): 24 25> JSON can represent four primitive types (strings, numbers, booleans, and null) and two structured types (objects and 26> arrays). 27 28Note that though strings are containers in C++, they are treated as primitive values in JSON. 29 30## Example 31 32??? example 33 34 The following code exemplifies `is_structured()` for all JSON types. 35 36 ```cpp 37 --8<-- "examples/is_structured.cpp" 38 ``` 39 40 Output: 41 42 ```json 43 --8<-- "examples/is_structured.output" 44 ``` 45 46## Version history 47 48- Added in version 1.0.0. 49