What is the difference between map and flatMap transformation in spark streaming?

Map and FlatMap are the transformation operations in Spark. Map() operation applies to each element of RDD and it returns the result as new RDD. While FlatMap() is similar to Map, but FlatMap allows returning 0, 1 or more elements from map function.

What is difference between flatMap () and map () functions?

map() function produces one output for one input value, whereas flatMap() function produces an arbitrary no of values as output (ie zero or more than zero) for each input value.

What is the difference between map and flatMap stream operation?

19 Answers. Both map and flatMap can be applied to a Stream and they both return a Stream . The difference is that the map operation produces one output value for each input value, whereas the flatMap operation produces an arbitrary number (zero or more) values for each input value.

What is the difference between MAP and flatMap and a good use case for each?

As per the definition, difference between map and flatMap is: map : It returns a new RDD by applying given function to each element of the RDD. Function in map returns only one item. flatMap : Similar to map , it returns a new RDD by applying a function to each element of the RDD, but output is flattened.

What does a flatMap do?

flatMap() is an intermediate operation and return another stream as method output return value. It returns a stream consisting of the results of replacing each element of the given stream with the contents of a mapped stream produced by applying the provided mapping function to each element.

What is the use of flatMap?

The flatMap() operation has the effect of applying a one-to-many transformation to the elements of the stream and then flattening the resulting elements into a new stream. Stream. flatMap() helps in converting Stream> to Stream .

Where is flatMap used?

We can use a flatMap() method on a stream with the mapper function List::stream. On executing the stream terminal operation, each element of flatMap() provides a separate stream. In the final phase, the flatMap() method transforms all the streams into a new stream.

What’s the difference between map and flatMap () in Rxjava?

Map returns an object of type T whereas a FlatMap returns an Observable . Using an observable operator we can also filter down the number of values we want to reach the observer. flatMap would be useful in android when you need to perform multiple network requests in parallel.

What is a flatMap in Scala?

flatMap() method is method of TraversableLike trait, it takes a predicate, applies it to each element of the collection and returns a new collection of elements returned by the predicate.

What is map and flatMap in spark with example?

flatMap in Spark, map transforms an RDD of size N to another one of size N . eg. myRDD.map(x => x*2) for example, if myRDD is composed of Doubles . While flatMap can transform the RDD into anther one of a different size: eg.: myRDD.flatMap(x =>new Seq(2*x,3*x))

What’s the difference between map and flatMap () in RxJava?

https://www.youtube.com/watch?v=txbwgouoGLE