#SCALA TUPLE FOR FREE#
#SCALA TUPLE CODE#

In absence of Tuple poor man choice was to create class with N number of instance variable and give them proper type, scala has Case class which is based on old school thought. Scala is using fixed number of parameter approach. Serialization overhead due to object type.

#SCALA TUPLE CODE#

Mutable unless framework or library generates code or maintain fixed layout objects like (Tuple, Tuple2, Tuple3…).Parameter are of object type so puts memory pressure.This is better than the first one but it also has few issues no types so serialization will be big overhead.parameter are of object type so puts memory pressure on both read and write.and has overhead of array index checking.This is first option that comes to my mind, it is good for flexibility but bad for performance like What are different ways to implement tuple ? Class with object array In this blog i will share dark side of tuple.

#SCALA TUPLE FOR FREE#

Nothing comes for free and every thing has some trade off. Nice thing about tuple is you have to only decided on data type of element not the name.Ĭomputer science has 2 hard problem : Cache invalidation and naming things. Elements in tuple can be of different type and very easy to declare like (“something”,1,new Date()) Map: is very powerful construct in programming language, it allows to create sequence of finite elements. This creates a Tuple2, which we can demonstrate in the REPL: In another cool feature, you can create a tuple using this syntax: The tuple toString method gives you a nice representation of a tuple: Scala> t.productIterator.foreach(println) Here's how you can iterate over the elements in a tuple: However, you can treat it a little bit like a collection by using its productIterator method. Iterating over a Scala tupleĪs mentioned, a tuple is not a collection it doesn't descend from any of the collection traits or classes. Or suppose you want to ignore the age and weight:Īgain, that's good stuff. Imagine you want to ignore the weight in our example: In a cool, related feature, if you only want to access some of the elements, you can ignore the others by using an underscore placeholder for the elements you want to ignore. It's shown in the REPL results, but we'll further confirm that we can indeed access the values by variable name: Scala> val(name, age, weight) = getUserInfo Now we can call that method, and assign the tuple results directly to variables, like this: To demonstrate the syntax, let's create a very simple method that returns a tuple: I like to do this when returning miscellaneous elements from a method. When referring to a Scala tuple you can also assign names to the elements in the tuple. Use variable names to access tuple elements Here’s a tuple that contains an Int and a String:īecause this contains two elements it creates a specific instance of a tuple called a Tuple2, which we can demonstrate in the REPL: You create a tuple with the following syntax, enclosing its elements in parentheses. I like to think of them as a little bag or container you can use to hold things and pass them around. In Scala 2 a tuple can contain up to 22 elements, and they can all be different types. Scala FAQ: Can you share some examples of using tuples in Scala? Getting started with Scala tuplesĪ Scala tuple is a class that can contain a miscellaneous collection of elements.

show more info on classes/objects in repl.