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Tuples in Scala

Scala Tuples: Tuple is a collection of similar or different multiple elements. Scala programming also supports tuples and in this Scala tutorials on tuples, we will learn about tuples with examples.
Submitted by Shivang Yadav, on July 20, 2019

Scala Tuples

A tuple is a data structure that has multiple elements. The elements of Scala tuples may or may not be the same data type.

The Scala tuples are immutable, i.e the objects of different type can be stored in the tuple but the value of these objects cannot be changed. The maximum number of miscellaneous elements that a tuple can have is twenty-two.

You can easily use tuples in your scala program for usage. The syntax for defining a tuple:

    val tuple_name = (data1, data2, data3, ...);

This is a shortcut way of defining a tuple. You can define a tuple by mentioning its tuple class, the class is simply tuples, where n is the number of elements the tuple has. For example,

    val tuple_name = new tuple2(data1, data2);

There is one more method to define a tuple by using the -> operator:

    val tuple_name = 'data1' -> 'data2';

Accessing the elements of a tuple

The access method for accessing an element of a tuple is quite easy and convenient. To access the element at no. n, you have to type in tuple._n, where the tuple is the name of a tuple and n^th element is fetched.

For example, if we need fetch 6^th element of the tuple t then we will type t._6 to access it.

Code to explain the initialization and accessing of tuples

object MyClass {
    def main(args: Array[String]) {
        val student = ("Ram", 10 ,92.4)
        println("Student name : "+student._1+" of the Standard "+student._2+" has scored "+student._3+"%")
    }
}

Output

Student name : Ram of the Standard 10 has scored 92.4%

Some helpful tuple methods and their syntax

1) tuple.productIterator()

It is used to iterate over the elements of a tuple.

Syntax:

    tuple.productIterator();

2) tuple.toString()

It is used to concatenate all the elements of the tuple into a string.

Syntax:

    tuple.toString();

3) tuple.swap()

It is used to swap two elements of a tuple.

Syntax:

    tuple.swap();

Example code to illustrate methods over a tuple

object MyClass {
    def main(args: Array[String]) {
        val student = ("Ram", 10);
        student.productIterator.foreach(println);
        var tuplestring = student.toString;
        println("\nThe concatenated string is"+tuplestring);
        val studentswap = student.swap;
        println("The swapped tuple is "+studentswap);
    }
}

Output

Ram
10

The concatenated string is(Ram,10)
The swapped tuple is (10,Ram)

Accessing variables using names

For ease of access, you can optionally assign the elements of a tuple name which can later be used to call them. This method is quite useful when you have a handful of elements in your tuple. Remembering names that are logically matching is easier than remembering the number. For example, a tuple has 5 elements and name is 3 elements. To access name, it is easier to remember the word rather than its sequence.

Syntax:

    def student  = ("Ram", 16, 76.12)
    val(name, age, percent) = getUserInfo;