json/docs/mkdocs/docs/api/basic_json/is_binary.md

nlohmann::basic_json::is_binary

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"
```

See also

• is_primitive checks whether the JSON value is primitive
• binary_t the type used to store binary values
• get_binary returns a reference to the stored binary value
• basic_json_view::is_binary - the same check on a zero-copy view

Version history

• Added in version 3.8.0.