# basic_json::is_binary ```cpp constexpr bool is_binary() const noexcept; ``` This function returns `#!cpp true` if and only if the JSON value is 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. ## Example ??? 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.