Creates a new dictionary from the key-value pairs in the given sequence, using a combining closure to determine the value for any duplicate keys.
- Xcode 10.2+
- Swift Standard Library
A sequence of key-value pairs to use for the new dictionary.
A closure that is called with the values for any duplicate keys that are encountered. The closure returns the desired value for the final dictionary.
You use this initializer to create a dictionary when you have a sequence of key-value tuples that might have duplicate keys. As the dictionary is built, the initializer calls the
combine closure with the current and new values for any duplicate keys. Pass a closure as
combine that returns the value to use in the resulting dictionary: The closure can choose between the two values, combine them to produce a new value, or even throw an error.
The following example shows how to choose the first and last values for any duplicate keys: