# nlohmann::basic_json::is_number_unsigned ```cpp constexpr bool is_number_unsigned() const noexcept; ``` This function returns `#!cpp true` if and only if the JSON value is an unsigned integer number. This excludes floating-point and signed integer values. If [`number_unsigned_t`](number_unsigned_t.md) is the same type as [`number_integer_t`](number_integer_t.md), every integer is stored as `number_integer_t`, and this function always returns `#!cpp false`. ## Return value `#!cpp true` if type is an unsigned integer number, `#!cpp false` otherwise. ## Exception safety No-throw guarantee: this member function never throws exceptions. ## Complexity Constant. ## Examples ??? example The following code exemplifies `is_number_unsigned()` for all JSON types. ```cpp --8<-- "examples/is_number_unsigned.cpp" ``` Output: ```json --8<-- "examples/is_number_unsigned.output" ``` ## See also - [is_number()](is_number.md) check if the value is a number - [is_number_integer()](is_number_integer.md) check if the value is an integer or unsigned integer number - [is_number_float()](is_number_float.md) check if the value is a floating-point number - [basic_json_view::is_number_unsigned](../basic_json_view/is_number_unsigned.md) - the same check on a zero-copy view ## Version history - Added in version 2.0.0.