Unquoted Keys

While this is not really data type, it is kind of convention allowing to use unquoted keys in complex structures.

If constant exists named same as key, the constant value will be used instead also be aware of self or static keywords.

Having above warning in mind, it is better to quote keys with single ' or double " quote . However most likely keys will be lowercase and constant uppercase, it is up to developer to use unquoted keys.

Example with JSON data

@SomeValue({one: 1, two: 2})

Will result in annotation value:

[
    'one' => 1,
    'two' => 2
]

Example with named parameter

@NamedValue(myValue = {one: 1, two: 2})

Will result in annotation value:

[
    'myValue' => [
        'one' => 1,
        'two' => 2
    ]
]