# nlohmann::basic_json::is_string ```cpp constexpr bool is_string() const noexcept; ``` This function returns `#!cpp true` if and only if the JSON value is a string. ## Return value `#!cpp true` if type is a string, `#!cpp false` otherwise. ## Exception safety No-throw guarantee: this member function never throws exceptions. ## Complexity Constant. ## Examples ??? example The following code exemplifies `is_string()` for all JSON types. ```cpp --8<-- "examples/is_string.cpp" ``` Output: ```json --8<-- "examples/is_string.output" ``` ## See also - [is_primitive](is_primitive.md) checks whether the JSON value is primitive - [type](type.md) returns the type of the JSON value - [string_t](string_t.md) the type used to store JSON strings ## Version history - Added in version 1.0.0.