# nlohmann::basic_json::is_binary
```cpp
constexpr bool is_binary() const noexcept;
```
This function returns `#!cpp true` if and only if the JSON value is a binary array.
## Return value
`#!cpp true` if type is binary, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this member function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The following code exemplifies `is_binary()` for all JSON types.
```cpp
--8<-- "examples/is_binary.cpp"
```
Output:
```json
--8<-- "examples/is_binary.output"
```
## Version history
- Added in version 3.8.0.