Object Functions

Object functions are used to manipulate objects/maps.

KEYS

keys(obj)

Return an array containing the keys of the map.

example:

keys({"a":1, "b":2})

result:

["a","b"]

VALUES

values(obj)

example:

values({"a":1, "b":2})

result:

[1,2]

Return an array containing the values of the map.

OBJECT

object(keys, values)

Construct an object from an array of keys and an array of values. Keys must be an array of strings. Values must be an arbitrary array of the same length as keys.

example:

object(["a","b"],[1,2])

result:

{"a":1, "b":2}

ZIP

zip(entries)

Construct an object from an array of entries. Each entry must itself be an array of size 2: the first element is the key (and must be a string), and the second element is the value.

example:

zip([["a",1],["b":2]])

result:

{"a":1, "b":2}

ITEMS

items(obj)

Return an array containing the entries of object. Each entry is a 2-element array; the first is the key, the second is the value.

example:

items({"a":1, "b":2})

result:

[["a",1],["b":2]]

OBJECT_CONSTRUCT

object_construct(key1, col1, key2, col2, ...)

Return a struct type object/map constructed by the arguments. The arguments are a series of key value pairs, thus the arguments count must be an odd number. The key must be a string, and the value can be of any type. If the value is null, the key/value pair will not present in the final object.

example:

object_construct("a", 1, "b", 2)

result:

{"a":1, "b":2}

OBJECT_CONCAT

object_concat(obj1, obj2, ...)

This function concatenates the input objects and returns a new object. It requires a minimum of two input objects. In cases where there are duplicate attribute names among the input objects, the attribute from the last relevant object in the input list is selected and copied to the output object. To illustrate, here's an example:

object_concat({"a": 1}, {"b": 2}, {"b": 3})

result:

{"a":1, "b":3}

ERASE

erase(obj, k)

If k is a string, return a new object where the key k is erased. If k is an array of strings, return a new object where the keys in k are erased.

erase({"baz": [1, 2, 3], "bar": 'hello world',"foo":'emq'}, 'foo')

result:

{"baz": [1, 2, 3], "bar": 'hello world'}

OBJECT_PICK

object_pick(obj, k)

If k is a string, return a new object where the key k is preserved. If k is an array of strings, return a new object where the keys in k are preserved.

object_pick({"baz": [1, 2, 3], "bar": 'hello world',"foo":'emq'}, 'foo')

result:

{"foo":'emq'}

OBJ_TO_KVPAIR_ARRAY

obj_to_kvpair_array(obj)

Return an array of key-value pairs converted from an object.

obj_to_kvpair_array({"key1":1, "key2":2})

result:

[{"key":"key1", "value":1},{"key":"key2", "value":2}]