Object literals allow you to construct an object with a set of properties.

Object literals function similar to JavaScript object literals.

Within the object literal, the following variables are available:

• this - A reference to the current object that can be used to reference previously defined properties.
• __parent__ - A reference to the parent object when used within a nested object literal.
• __root__ - A reference to the top-level object when used within a deeply nested object literal.

An object literal is a comma-delimited list of zero or more pairs of property names and values surrounded by curly braces ({}), like so:

{
    property-name1 : value1,
    property-name2 : value2,
    ...
    property-nameN : valueN,
}

The property name can be computed dynamically by enclosing an expression in square brackets ([]), like so:

[expression] : value

The result of the expression will be converted into a string.

Input:

let user = {
	name: "John",
	age: 30
}

Expression: $user.entries()
Result: [ ["name","John"], ["age",30] ]

Returns a new object with the properties of the current one merged with the properties of the objects that were passed in. This is similar to http://underscorejs.org/#extend, but the extend object method returns a new object instead of modifying the given one. 

The extend object method can also be used to convert an array of objects into an object. An example illustrating the same is described in the Example Use Cases section below.

Expression: $.extend({ newField1 : 'foo' }, { newField2 : 'bar' })

Input:

{}

Result:

{
      "newField1": "foo",
      "newField2": "bar"
}

{}.extend({ newField1 : 'foo' },{ newField2 : 'bar' })

Get the value of a property or a default value if the object does not have the given property. If no default value is given, null is returned.

See also: Checking for optional properties and returning defaults in the expression language

Find the value for the given property name. If the property does not exist, the function returns the default value (if given); otherwise, null is returned. If the value is a populated list, then the function returns the first value in the list; otherwise, it returns the default value if present or null.

Returns a boolean value to indicate whether the object has the specified property.

The in operator and get method can be used as a shorthand to test if an object has a property or get the value of a property with a default if it does not exist.

Returns true if the given object has no properties.

object.filter(callback)

• callback - A function that takes three arguments (property-value, property-name, input-object) and returns true if the property should be included in the returned object or false if it should be left out.

Expression: $.filter((value, key) => key.startsWith("new"))

Input:

{
      "key1": "abc",
      "key2": "xyz",
	  "newField1": "foo",
      "newField2": "bar"
    }

Result:

{
      "newField1": "foo",
      "newField2": "bar"
    }

Input:

let user = {
	name: "John",
	age: 30
}

Expression: $user.keys()
Result: [name, age]

object.mapKeys(callback)

• callback - A function that takes three arguments (property-value, property-name, input-object) and returns the new value for the property key.

Expression: $.mapKeys((value, key) => "new" + key)

Input:

{
      "Field1": "foo",
      "Field2": "bar"
    }

Result:

{
      "newField1": "foo",
      "newField2": "bar"
    }

object.mapValues(callback)

• callback - A function that takes three arguments (property-value, property-name, input-object) and returns the new value for the property.

Expression: $.mapValues((value, key) => key == "newField1" ? "foo" : "bar")

Input:

{
      "newField1": "abc",
      "newField2": "xyz"
    }

Result:

{
      "newField1": "foo",
      "newField2": "bar"
    }

object.merge(obj1, ..., objN)

.

Expression: $.merge({child: {age: 32}})

Input:

{
    "id": 12345,
    "child": {
        "name": "John Doe"
    }
}

Result:

{
    "id": 12345,

    "child": {
        "name": "John Doe",
        "age": 32
    }
}

Input:

[{“user”: {
    “name”: "John",
    “age”: 30
    }
}]

Expression: $user.values()
Result: ["John", 30]