JSONPath Guide
JSONPath expressions always refer to a JSON structure. 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 Notation
A JSONPath expression specifies a path to an element (or a set of elements) in a JSON structure. Paths can use the dot notation:
$.store.book[0].title
or the bracket notation:
$['store']['book'][0]['title']
The leading $ represents the root object or array and can be omitted. For example, $.foo.bar and foo.bar are the same, and so are $[0].status and [0].status.
Other syntax elements are described below.
| Expression | Description |
|---|---|
$ | The root object or array. |
.property | Selects the specified property in a parent object. |
['property'] | Selects the specified property in a parent object. Be sure to put single quotes around the property name. Tip: Use this notation if the property name contains special characters such as spaces, or begins with a character other than A..Za..z_. |
[n] | Selects the n-th element from an array. Indexes are 0-based. |
[index1,index2,…] | Selects array elements with the specified indexes. Returns a list. |
..property | Recursive descent: Searches for the specified property name recursively and returns an array of all values with this property name. Always returns a list, even if just one property is found. |
* | Wildcard selects all elements in an object or an array, regardless of their names or indexes. For example, address* means all properties of the address object, and book[*] means all items of the book array. |
[start:end][start:] | Selects array elements from the start index and up to, but not including, end index. If end is omitted, selects all elements from start until the end of the array. Returns a list. |
[:n] | Selects the first n elements of the array. Returns a list. |
[-n:] | Selects the last n elements of the array. Returns a list. |
[?(expression)] | Filter Expression. Selects all elements in an object or array that match the specified filter. Returns a list. |
[(expression)] | Script expressions can be used instead of explicit property names or indexes. An example is [(@.length-1)] which selects the last item in an array. Here, length refers to the length of the current array rather than a JSON field named length. |
@ | Used in filter expressions to refer to the current node being processed. |
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JSONPath expressions, including property names and values, are case-sensitive.
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Unlike XPath, JSONPath does not have operations for accessing parent or sibling nodes from the given node.
Filters
Filters are logical expressions used to filter arrays. An example of a JSONPath expression with a filter is:
$.store.book[?(@.price < 10)]
where @ represents the current array item or object being processed. Filters can also use $ to refer to the properties outside of the current object:
$.store.book[?(@.price < $.expensive)]
An expression that specifies just a property name, such as [?(@.isbn)], matches all items that have this property, regardless of the value.
Additionally, filters support the following operators:
| Expression | Description |
|---|---|
== | Equals to .1 and '1' are considered equal. String values must be enclosed in single quotes (not double quotes):[?(@.color=='red')]. |
!= | Not equal to. String values must be enclosed in single quotes. |
> | Greater than. |
>= | Greater than or equal to. |
< | Less than. |
<= | Less than or equal to. |
=~ | Match a JavaScript regular expression. For example, [?(@.description =~ /cat.*/i)] matches items whose description starts with cat (case-insensitive). |
! | Use to negate a filter: [?(!@.isbn)] matches items that do not have the isbn property. |
&& | Logical AND, used to combine multiple filter expressions: [?(@.category=='fiction' && @.price < 10)] |
| || | Logical OR, used to combine multiple filter expressions: [?(@.category=='fiction' || @.price < 10)] |
Examples
Sample JSON Example
{
"store": {
"book": [
{
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{
"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
}
},
"expensive": 10
}
In all these examples, the leading $. is optional and can be omitted.
| Expression | Meaning |
|---|---|
$..book[0] | The first book. Result: [ { "category":"reference", "author":"Nigel Rees", "title":"Sayings of the Century", "price":8.95 } ] |
$..book[0].title | The title of the first book. Result: Sayings of the Century |
$..book[0,1].title$..book[:2].title | The titles of the first two books. Result: [Sayings of the Century, Moby Dick] |
$..book[-1:].title$..book[(@.length-1)].title | The title of the last book. Result: [The Lord of the Rings] The result is a list, because [-n:] always returns lists. |
$..book[?(@.author=='J.R.R. Tolkien')].title | The titles of all books by J.R.R. Tolkien (exact match, case-sensitive). Result: [The Lord of the Rings] The result is a list, because filters always return lists. |
$..book[?(@.isbn)] | All books that have the isbn property. |
$..book[?(!@.isbn)] | All books without the isbn property. |
$..book[?(@.price < 10)] | All books cheaper than 10. |
$..book[?(@.price > $.expensive)] | All expensive books. |
$..book[?(@.author =~ /.\*Tolkien/i)] | All books whose author name ends with Tolkien (case-insensitive). |
$..book[?(@.category == 'fiction' || @.category == 'reference')] | All fiction and reference books. |
$..* | All members of the JSON structure beneath the root (child objects, individual property values, array items), combined into an array. |
JSONPath Expressions that Return Multiple Elements
JSONPath queries can return not just a single element, but also a list of matching elements. For example, given this JSON:
{
"name": "Rose Kolodny",
"phoneNumbers": [
{
"type": "home",
"number": "954-555-1234"
},
{
"type": "work",
"number": "754-555-5678"
}
]
}
the JSONPath expression:
phoneNumbers[\*].number
returns a list containing two phone numbers:
[954-555-1234, 754-555-5678]
How to Check JSONPath Syntax
You can use http://jsonpath.herokuapp.com and check the results on the Jayway tab whether JSONPath syntax is valid.
