JSON Path variables

JSON Path is used to define what data a response variable should include. 

Example the payload below:

{ "new": [ { "attributes": { "type": "Case", "url": "/services/data/v52.0/sobjects/Case/5002p00002b6ALIAA2" }, "Origin": "Phone", "Status": "New", "LastModifiedDate": "2021-10-07T09:13:38.000+0000", "IsDeleted": false, "Description": "with something", "Priority": "Medium", "IsClosed": false, "Subject": "I need help", "SystemModstamp": "2021-10-07T09:13:38.000+0000", "BusinessHoursId": "01m2p000000JHh2AAG", "CreatedById": "0052p000008e5mPAAQ", "IsEscalated": false, "OwnerId": "0052p000008e5mPAAQ", "CreatedDate": "2021-10-07T09:13:38.000+0000", "IsClosedOnCreate": false, "CaseNumber": "00001098", "Id": "5002p00002b6ALIAA2", "LastModifiedById": "0052p000008e5mPAAQ" } ], "old": [], "userId": "0052p000008e5mPAAQ" }

Picking the value caseNumber, then we need to look at the new array first element and pick the CaseNumber

 

JSON Path with spaces in variable name

If the payload contains variables with spaces like the example below;

{
	"values": {
		"Incident Number": "INC00456789098765"
	}
}

Then use $.values["Incident Number"] to fetch the value in the JSON path.

Operators

Operator

Description

$

The root element to query. This starts all path expressions.

@

The current node being processed by a filter predicate.

*

Wildcard. Available anywhere a name or numeric are required.

..

Deep scan. Available anywhere a name is required.

.<name>

Dot-notated child

['<name>' (, '<name>')]

Bracket-notated child or children

[<number> (, <number>)]

Array index or indexes

[start:end]

Array slice operator

[?(<expression>)]

Filter expression. Expression must evaluate to a boolean value.

Functions

Functions can be invoked at the tail end of a path - the input to a function is the output of the path expression. The function output is dictated by the function itself.

Function

Description

Output

min()

Provides the min value of an array of numbers

Double

max()

Provides the max value of an array of numbers

Double

avg()

Provides the average value of an array of numbers

Double

stddev()

Provides the standard deviation value of an array of numbers

Double

length()

Provides the length of an array

Integer

Filter Operators

Filters are logical expressions used to filter arrays. A typical filter would be [?(@.age > 18)] where @ represents the current item being processed. More complex filters can be created with logical operators && and ||. String literals must be enclosed by single or double quotes ([?(@.color == 'blue')] or [?(@.color == "blue")]).

Operator

Description

==

left is equal to right (note that 1 is not equal to '1')

!=

left is not equal to right

<

left is less than right

<=

left is less or equal to right

>

left is greater than right

>=

left is greater than or equal to right

=~

left matches regular expression [?(@.name =~ /foo.*?/i)]

in

left exists in right [?(@.size in ['S', 'M'])]

nin

left does not exists in right

subsetof

left is a subset of right [?(@.sizes subsetof ['S', 'M', 'L'])]

anyof

left has an intersection with right [?(@.sizes anyof ['M', 'L'])]

noneof

left has no intersection with right [?(@.sizes noneof ['M', 'L'])]

size

size of left (array or string) should match right

empty

left (array or string) should be empty

Path Examples

Given the json

{ "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 } }, "expensive": 10 }

JsonPath (click link to try)

Result

$.store.book[*].author

The authors of all books

$..author

All authors

$.store.*

All things, both books and bicycles

$.store..price

The price of everything

$..book[2]

The third book

$..book[-2]

The second to last book

$..book[0,1]

The first two books

$..book[:2]

All books from index 0 (inclusive) until index 2 (exclusive)

$..book[1:2]

All books from index 1 (inclusive) until index 2 (exclusive)

$..book[-2:]

Last two books

$..book[2:]

Book number two from tail

$..book[?(@.isbn)]

All books with an ISBN number

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

All books in store cheaper than 10

$..book[?(@.price <= $['expensive'])]

All books in store that are not "expensive"

$..book[?(@.author =~ /.*REES/i)]

All books matching regex (ignore case)

$..*

Give me every thing

$..book.length()

The number of books

Some examples

Last item in an array

Path

Description

$.comments[-1:].body

Example usage of getting the last comment


ServiceNow example: ServiceNow - Get last short_description


Further reading