Creating Tuples

A tuple groups a fixed number of values together, even when those values have different types.

Unlike a list, where every element shares one type, a tuple can hold an Int, a String, and a Boolean all at once.

Tuples are perfect for returning or bundling a handful of related values without writing a whole class.

You build a tuple by wrapping comma-separated values in parentheses.

Here we pair a name with an age. Scala figures out the types automatically.

One of the best features of tuples is mixing types in a single value.

This tuple holds a String, an Int, and a Boolean together. Each slot keeps its own type.

The type of a tuple shows every element type in order.

A pair of a String and an Int has type (String, Int). You can write the type explicitly if you want to be clear.

A tuple with exactly two elements is called a pair, and pairs appear everywhere in Scala.

For example, maps are built from key-value pairs. Learning pairs first makes the rest of the language easier.

For two-element tuples, Scala offers a handy arrow syntax.

Writing key -> value is exactly the same as (key, value). It reads nicely, especially when building maps.

Tuples can hold more than two or three values.

Scala supports tuples up to 22 elements, though small tuples are easiest to read. If you need many fields, a case class is usually clearer.

There is no useful one-element tuple. Putting one value in parentheses just gives you that value back.

So (5) is simply the number 5, not a tuple. Tuples really start at two elements.

Once you create a tuple, its values never change.

This immutability makes tuples safe to share and easy to reason about. To get a different tuple, you simply build a new one.

A common use of tuples is returning several values from a function at once.

Here a function returns both a sum and a product as a single tuple, avoiding the need for a separate class.

Because a tuple is just a value, you can place a tuple inside another tuple.

This lets you group related sub-pairs together. Keep nesting shallow so your code stays readable.

Test what you learned about creating tuples.

You learned that tuples group a fixed number of values of possibly different types inside parentheses.

Pairs can also use key -> value syntax, tuples are immutable, and they are great for returning multiple values. Next you will learn how to pull those values back out.