WebOct 7, 2024 · It will return Some(value) when the key exists in the Map, and None when it doesn’t exist. Option and None are briefly explained in The Option Type in Scala. To clarify, we’ve seen that there will be two data types when working with a Map – the key and the value. 3. Higher-Order Functions Iteration WebJul 23, 2024 · To update a key/value pair with an immutable map, reassign the key and value while using the + method, and the new values replace the old: scala> val d = c + ("AR" -> "banana") d: scala.collection.immutable.Map [String,String] = Map (AL -> Alabama, AK -> Alaska, AR -> banana, AZ -> Arizona) To remove one element, use the - method: scala> val …
Scala: How to add, update, and remove elements with immutable Maps …
WebFor instance, the get method of Scala's Map produces Some (value) if a value corresponding to a given key has been found, or None if the given key is not defined in the Map. Option type is used frequently in Scala programs and you can compare this with the null value available in Java which indicate no value. WebAug 13, 2024 · Scala Map keys () method with example Last Updated : 13 Aug, 2024 Read Discuss Courses Practice Video The keys () method is utilized to give an iterator over all the keys of the map. Method Definition: def keys: Iterable [A] Return Type: It returns an iterator over all the keys of the map. Example #1: object GfG { def main (args:Array [String]) { is spectrum a part of charter communications
Scala map contains() method with example
WebJul 29, 2024 · The exists () method is utilized to check if the given predicate satisfy the elements of the list or not. Method Definition: def exists (p: (A) => Boolean): Boolean Return Type: It returns true if the stated predicate holds true for some elements of the list else it returns false. Example #1: object GfG { def main (args:Array [String]) { WebOct 22, 2024 · Now that you have added mapping, its time to check is key exists in the ConcurrentHashMap or not. This time we will use the containsKey () method from the Map interface which is also... WebJul 23, 2024 · Keys: states.keySet # Set[String] = Set(AK, AL, AR) states.keys # Iterable[String] = Set(AK, AL, AR) states.keysIterator # Iterator[String] = non-empty iterator Values: states.values # Iterable[String] = MapLike.DefaultValuesIterable(Alaska, Alabama, Arkansas) states.valuesIterator # Iterator[String] = non-empty iterator is spectrum and charter the same