JSON Path Specification¶

JSON Path is a query language for JSON documents.

Selectors¶

Selectors	Description
`$`	The root object
`@`	The current object
`.<name>`	Dot-notated child
`[<string>]`	Bracket-notated child
`[<number>]`	Array index
`[start:end]`	Array slice
`[start:end:step]`	Extended array slice
`[<expression>]`	Filter
`{<expression>}`	Non-descending filter
`?`	Existence check

Examples¶

{
    "books": [
        {
            "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
        }
    ],
    "'~'": "value"
}

JSON Path	Result
`$.books[@]`	All books
`$.books[:].author`	The authors of all books
`$.books[2]`	The third book
`$.books[-1]`	The last book
`$.books[:2]`	The first two books
`$.books[@.isbn]`	All books with an ISBN
`$.books[:].isbn?`	The ISBNs of all books with an ISBN
`$.books[@.price < 10]`	All books cheaper than 10
`$.books[:].price{@ < 10}`	The prices of all books cheaper than 10
`$.books[@.category == 'fiction' && @.price < 20]`	All fiction books cheaper than 20
`$['~'~~~'']`	The value of the key `'~'`

Grammar¶

Generated with RR - Railroad Diagram Generator by Gunther Rademacher.

query¶

A query can be absolute or relative.

query ::= absolute_query | relative_query

absolute_query¶

An absolute query starts with $ followed by zero or more selectors.

absolute_query ::= '$' ( '?'? (
                   '.' identifier
                   | '{' filter '}'
                   | '[' ( slice | integer | string | filter ) ']' )
                   )* '?'?

relative_query¶

A relative query starts with @ followed by zero or more child selectors.

relative_query ::= '@' ( '.' identifier | '[' ( slice | string | integer ) ']' )*

filter¶

A filter consists of one or more (non-)existence checks / comparisons.

filter ::= (
           '!'? relative_query
           | relative_query whitespace operator whitespace value
           ) ++ ( whitespace '&&' whitespace )

value¶

A value can be a string, number, true, false or null.

value ::= string | number | 'true' | 'false' | 'null'

slice¶

A slice has a start and an end index (exclusive) with an optional step.

slice ::= integer? ':' integer? ( ':' integer? )?

string¶

A string is a sequence of characters, wrapped in single quotes, using tilde escapes.

string ::= "'" ( [^'~] | '~' ['~] )* "'"

integer¶

An integer is a signed decimal number.

integer ::= '-'? ( '0' | [1-9] [0-9]* )

number¶

A number is a signed decimal number, optionally in scientific notation or one of the special values Infinity and -Infinity.

number ::= '-'? (
           ( '0' | [1-9] [0-9]* ) ( '.' [0-9]+ )? ( [eE] [+-]? [0-9]+ )?
           | 'Infinity'
           )

operator¶

An operator can be <=, <, ==, !=, >= or >.

operator ::= '<=' | '<' | '==' | '!=' | '>=' | '>'

whitespace¶

Whitespace can be inserted around operators.

whitespace ::= '#x20'*