JSONPath

This project is a C# implementation of JSONPath.

JSONPath Expressions

Portions © 2006 Stefan Gössner

JSONPath expressions always refer to a JSON structure in the same way as XPath expression are used in combination with an XML document. Since a JSON structure is usually anonymous and doesn't necessarily have a root member object JSONPath assumes the abstract name $ assigned to the outer level object.

JSONPath expressions can use the dot-notation:

$.store.book[0].title

or the bracket-notation:

$['store']['book'][0]['title']

for input paths. Internal or output paths will always be converted to the more general bracket-notation.

JSONPath allows the wildcard symbol * for member names and array indices. It borrows the descendant operator .. from E4X and the array slice syntax proposal [start:end:step] from ECMASCRIPT 4.

Expressions of the underlying scripting language (<expr>) can be used as an alternative to explicit names or indices, as in:

$.store.book[(@.length-1)].title

using the symbol @ for the current object. Filter expressions are supported via the syntax ?(<boolean expr>), as in:

$.store.book[?(@.price < 10)].title

Below is a complete overview and a side-by-side comparison of the JSONPath syntax elements with its XPath counterparts:

Examples

Portions © 2006 Stefan Gössner

Let's practice JSONPath expressions by some more examples. We start with a simple JSON structure built after an XML example representing a bookstore:

{ "store": {
    "book": [
      { "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      { "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      },
      { "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      { "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}