What is a mutable map?

What is a mutable map?

Kotlin MutableMap is an interface of collection framework that holds the object in the form of key and value pair. The key and value may be of different pairs such as ,, etc.

How do you count occurrences in Scala?

The count() method in Scala is used to count the occurrence of characters in the string. The function will return the count of a specific character in the string.

How do you count number of elements in a spark sequence?

6. Count the number of elements in an RDD

1. . count() method is Spark’s action. It counts the number of elements of an RDD.
2. It returns a Long integer. Therefore, we can simply print it out.

What is flatMap Scala?

In Scala, flatMap() method is identical to the map() method, but the only difference is that in flatMap the inner grouping of an item is removed and a sequence is generated. It can be defined as a blend of map method and flatten method.

How do I sort a list in Scala?

The sorted function is used to sort the sequence in Scala like (List, Array, Vector, Seq). The sorted function returns new Collection which is sorted by their natural order.

What is spark mapValues?

mapValues. RDD. mapValues (f)[source] Pass each value in the key-value pair RDD through a map function without changing the keys; this also retains the original RDD’s partitioning.

How do I count distinct values in spark?

distinct() runs distinct on all columns, if you want to get count distinct on selected columns, use the Spark SQL function countDistinct() . This function returns the number of distinct elements in a group.

How to read a mutable map in Scala?

Use a mutable map to count how often each word appears. To read the words, simply use a java.util.Scanner create a file in /tmp called quote.txt before running this example: By default, Maps are read only. Here, we import the proper package and rename the Map to MutableMap to avoid confusion import scala.collection.

What does a mutableiterator do in mutablemap?

Returns a MutableIterator over the mutable entries in the MutableMap. Returns a list containing the results of applying the given transform function to each entry in the original map. Returns a new Map with entries having the keys obtained by applying the transform function to each entry in this Map and the values of this map.

How is a mutable map invariant in its value type?

The mutable map is invariant in its value type. Represents a key/value pair held by a MutableMap. Returns a MutableSet of all key/value pairs in this map. Returns a MutableSet of all keys in this map. Returns a MutableCollection of all values in this map. Note that this collection may contain duplicate values. Removes all elements from this map.

How do you append pairs to a mutable map?

Appends or replaces all pairs from the given collection of pairs in this mutable map. Appends or replaces all pairs from the given array of pairs in this mutable map. Appends or replaces all pairs from the given sequence of pairs in this mutable map.