JSON Pointer · lesson 5 of 6 · When it doesn't work

What pointers can't do

A pointer names one exact location. There is no negative index, no wildcard and no filter — for those, use JSONPath, jq or JMESPath.

Example 1No negative indexes

Document

{
  "store": {
    "book": [
      { "title": "Moby Dick", "price": 8.99 },
      { "title": "Ulysses", "price": 12.5 }
    ],
    "bicycle": { "color": "red" }
  }
}

Query

/store/book/-1

-1 RFC 6901 has no negative indexes (jq has .[-1], JSONPath [-1]).

Result (it fails on purpose)

query error: no value at pointer '/store/book/-1'

Try it in the playground

Example 2No wildcards

Document

{
  "store": {
    "book": [
      { "title": "Moby Dick", "price": 8.99 },
      { "title": "Ulysses", "price": 12.5 }
    ],
    "bicycle": { "color": "red" }
  }
}

Query

/store/book/*/title

* * is looked up as an ordinary key literally named *, which doesn't exist.

Result (it fails on purpose)

query error: no value at pointer '/store/book/*/title'

Try it in the playground

Good to know

A lone - (as in /store/book/-) means "the position after the last element" — meaningful when adding with JSON Patch, but never a readable value.
Want every title? JSONPath: $.store.book[*].title · jq: .store.book[].title · JMESPath: store.book[*].title.