List of Built-in Functions

While there are some extensions made to the JMESPath query language in DocuMotor, a lot of functionality is documented at jmespath.org.

You can find information on each specific function by following the links below.

JMESPath	Reference	Output
abs	number abs(number $value)	Returns the absolute value of the provided argument.
avg	number avg(array[number] $elements)	Returns the average of the elements in the provided array.
contains	boolean contains(array|string $subject, any $search)	Returns true if the given $subject contains the provided $search string. If $subject is an array, this function returns true if one of the elements in the array is equal to the provided $search value. If the provided $subject is a string, this function returns true if the string contains the provided $search argument.
ceil	number ceil(number $value)	Returns the next highest integer value by rounding up if necessary.
ends_with	boolean ends_with(string $subject, string $prefix)	Returns true if the $subject ends with the $prefix, otherwise this function returns false.
floor	number floor(number $value)	Returns the next lowest integer value by rounding down if necessary.
join	string join(string $glue, array[string] $stringsarray)	Returns all of the elements from the provided $stringsarray array joined together using the $glue argument as a separator between each.
keys	array keys(object $obj)	Returns an array containing the keys of the provided object. Note that because JSON hashes are inheritently unordered, the keys associated with the provided object obj are inheritently unordered. Implementations are not required to return keys in any specific order.
length	number length(string|array|object $subject)	Returns the length of the given argument using the following types rules: string: returns the number of code points in the string array: returns the number of elements in the array object: returns the number of key-value pairs in the object
map	array[any] map(expression->any->any expr, array[any] elements)	Apply the expr to every element in the elements array and return the array of results. An elements of length N will produce a return array of length N. Unlike a projection, ([*].bar), map() will include the result of applying the expr for every element in the elements array, even if the result if null.
max	number max(array[number]|array[string] $collection)	Returns the highest found number in the provided array argument. An empty array will produce a return value of null.
max_by	max_by(array elements, expression->number|expression->string expr)	Return the maximum element in an array using the expression expr as the comparison key. The entire maximum element is returned.
merge	object merge([object *argument, [, object $...]])	Accepts 0 or more objects as arguments, and returns a single object with subsequent objects merged. Each subsequent object’s key/value pairs are added to the preceding object. This function is used to combine multiple objects into one. You can think of this as the first object being the base object, and each subsequent argument being overrides that are applied to the base object.
min	number min(array[number]|array[string] $collection)	Returns the lowest found number in the provided $collection argument.
min_by	min_by(array elements, expression->number|expression->string expr)	Return the minimum element in an array using the expression expr as the comparison key. The entire maximum element is returned.
not_null	any not_null([any $argument [, any $...]])	Returns the first argument that does not resolve to null. This function accepts one or more arguments, and will evaluate them in order until a non null argument is encounted. If all arguments values resolve to null, then a value of null is returned.
reverse	array reverse(string|array $argument)	Reverses the order of the $argument.
sort	array sort(array[number]|array[string] $list)	This function accepts an array $list argument and returns the sorted elements of the $list as an array. The array must be a list of strings or numbers. Sorting strings is based on code points. Locale is not taken into account.
sort_by	sort_by(array elements, expression->number|expression->string expr)	Sort an array using an expression expr as the sort key. For each element in the array of elements, the expr expression is applied and the resulting value is used as the key used when sorting the elements. If the result of evaluating the expr against the current array element results in type other than a number or a string, an invalid-type error will occur.
starts_with	boolean starts_with(string $subject, string $prefix)	Returns true if the $subject starts with the $prefix, otherwise this function returns false.
sum	number sum(array[number] $collection)	Returns the sum of the provided array argument. An empty array will produce a return value of 0.
to_array	array to_array(any $arg)	array – Returns the passed in value. number/string/object/boolean – Returns a one element array containing the passed in argument.
to_string	string to_string(any $arg)	string – Returns the passed in value. number/array/object/boolean – The JSON encoded value of the object. The JSON encoder should emit the encoded JSON value without adding any additional new lines.
to_number	number to_number(any $arg)	string – Returns the parsed number. Any string that conforms to the json-number production is supported. number – Returns the passed in value. array – null object – null boolean – null null – null
type	string type(array|object|string|number|boolean|null $subject)	Returns the JavaScript type of the given $subject argument as a string value. The return value MUST be one of the following: number string boolean array object null
values	array values(object $obj)	Returns the values of the provided object. Note that because JSON hashes are inheritently unordered, the values associated with the provided object obj are inheritently unordered. Implementations are not required to return values in any specific order.