Scala For Loop Overview

The for loop in Scala is a powerful and flexible construct used for iterating over collections or performing repetitive tasks. This guide covers the essential aspects of using for loops in Scala, ensuring you can utilize them effectively in your programming.

Key Concepts

• Basic Syntax: The basic structure of a for loop in Scala is straightforward.
• Iteration: You can iterate over collections like arrays, lists, and ranges.
• Yielding Values: The for loop can be used to create new collections by yielding values.
• Nested Loops: Scala allows for nested for loops, enabling complex iterations.

Basic Syntax

The basic syntax of a for loop is as follows:

for (variable <- collection) {
  // Code to execute for each element
}

Example:

val numbers = List(1, 2, 3, 4, 5)
for (number <- numbers) {
  println(number)
}

This code will print each number in the list.

Iterating Over Ranges

Scala allows you to easily create ranges and iterate through them:

for (i <- 1 to 5) {
  println(i)
}

Output:

1
2
3
4
5

Yielding Values

You can use a for loop to create a new collection by using the yield keyword:

val doubledNumbers = for (number <- numbers) yield number * 2
println(doubledNumbers) // Output: List(2, 4, 6, 8, 10)

Nested Loops

Scala supports nested for loops, allowing you to iterate over multiple collections:

val colors = List("Red", "Green", "Blue")
for (color <- colors; number <- 1 to 3) {
  println(s"$color $number")
}

Output:

Red 1
Red 2
Red 3
Green 1
Green 2
Green 3
Blue 1
Blue 2
Blue 3

Conclusion

The for loop in Scala is a versatile tool for iteration, providing various methods to handle collections efficiently. Whether you're simply printing elements or creating new collections, understanding the for loop is essential for effective Scala programming.