# nlohmann::json_pointer::json_pointer ```cpp explicit json_pointer(const string_t& s = ""); ``` Create a JSON pointer according to the syntax described in [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). ## Parameters `s` (in) : string representing the JSON pointer; if omitted, the empty string is assumed which references the whole JSON value ## Exceptions - Throws [parse_error.107](../../home/exceptions.md#jsonexceptionparse_error107) if the given JSON pointer `s` is nonempty and does not begin with a slash (`/`); see example below. - Throws [parse_error.108](../../home/exceptions.md#jsonexceptionparse_error108) if a tilde (`~`) in the given JSON pointer `s` is not followed by `0` (representing `~`) or `1` (representing `/`); see example below. ## Examples ??? example The example shows the construction several valid JSON pointers as well as the exceptional behavior. ```cpp --8<-- "examples/json_pointer.cpp" ``` Output: ```json --8<-- "examples/json_pointer.output" ``` ## Version history - Added in version 2.0.0. - Changed type of `s` to `string_t` in version 3.11.0.