JSON Query

Pulling values out by path

When you only need one field buried in a large response, parsing the whole thing in code is overkill. A path query lets you address a value directly: dot notation to step into objects, bracket indexes to reach array elements, and wildcards to collect many matches at once. It is the read side of JSON, no mutation, just extraction.

Example

Given this data:

{
  "users": [
    { "name": "Ada", "roles": ["dev"] },
    { "name": "Lin", "roles": ["lead", "dev"] }
  ]
}

Queries and results:

users[0].name      -> "Ada"
users[1].roles[0]  -> "lead"
users[*].name      -> ["Ada", "Lin"]

Dot paths versus the real thing

Simple dot-and-bracket paths cover most needs, but they are not JSONPath or jq. There is no filtering ("users where role is lead"), no arithmetic, no recursion into unknown depth beyond a wildcard. If your selection needs conditions, you have outgrown dot paths and want a full query language. Knowing that boundary saves time fighting a tool that cannot do what you need.

Keys that break dot notation

A key with a dot or space in its name, like "user.name", cannot be reached with plain dot syntax because the dot is read as a step. Those keys need bracket access, and some tools do not support quoted bracket keys at all, which is a hard wall worth checking before you rely on it.

FAQ

What does a wildcard return? An array of every match, even if there is only one. Code consuming it should expect a list, not a single value.

What if the path does not exist? Most tools return nothing or undefined rather than erroring, so a silent empty result usually means a typo in the path or a wrong index.