Resolve one exact JSON Pointer

JSON Pointer represents a sequence of reference tokens from the root of a JSON document. Each slash moves to one object member or array position. The evaluation therefore produces one exact value when every token exists, rather than a collection of possible matches.

The empty string has a defined meaning: it identifies the whole document. A non-empty pointer must begin with `/`. Array tokens use non-negative decimal indexes without a leading zero, while object tokens are matched as member names after escape decoding.

A member name may itself contain `/` or `~`, the two characters used by pointer syntax. RFC 6901 replaces a tilde with `~0` and a slash with `~1` inside a token. Decoding happens in that order so `~01` represents the literal text `~1`, not a slash.

Build pointers from member-name tokens rather than applying a broad string replacement to a complete path. Tests should include empty member names, slashes, tildes, numeric-looking object names, missing locations, and arrays with boundary indexes.

Pointer works well for patch operations, error locations, schema references, and interfaces that already know one location. It cannot express a wildcard or filter. JSONPath is the better model when the job is to query a document and return a nodelist.

The selected value stays local, but it may still contain sensitive information. Avoid sharing a pointer plus source document when the combination reveals a secret path or privileged field. Authorize access before evaluating a pointer on a server.