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Solution Review: Array of Squares

Explore how to implement a for expression in Scala to iterate through an array and square each of its elements. Understand the use of ranges, zero-based indexing, and assigning results back to the array. This lesson helps you strengthen your grasp of Scala control flow and array manipulation.

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Task

In this challenge, you were provided an array of numbers which needed to be squared.

Solution

Let’s go over the solution step-by-step.

  • The first thing you had to figure out is that this problem requires a for expression.

  • Next, you had to figure out the number of iterations required for the program to return the correct output. As each element of the array needed to be squared, the number of times the for expression should run is equivalent to the length of the array.

for (i <- 0 until testArray.length)

To create our range for the iterator i we use the Range keyword until. This is because the last index of an array is one less than its length as indexes start from 0 and length starts from 1. As we already know from a previous lesson, until excludes the upper limit.

  • Finally, the last step required you to assign the square of the value at an index to the same index.
testArray(i) = testArray(i)*testArray(i)

You can find the complete solution below:

You were required to write the code from line 3 to line 5.

Scala
val testArray = Array(1,2,3)
for (i <- 0 until testArray.length) {
  testArray(i) = testArray(i) * testArray(i)
}
// Driver Code
testArray.foreach(println)

In the next lesson, we will learn about the try control structure.