Hello and welcome! In our journey today, we'll delve into multidimensional arrays in Scala, a powerful metaphor for a chessboard in programming. Our objective is to enable you to create, access, and modify these diverse arrays. Get ready and let's dive in!
Think of a multidimensional array as an array of arrays. Similar to a chessboard, each square, identifiable via its row and column coordinates, stands for a specific value or chess piece. Let's not forget, this 2D visualization is not limiting us. Scala allows creating arrays with 3, 4, or even more dimensions, smoothly extending this concept.
In Scala, you can declare multidimensional arrays using the Array keyword along with parentheses to group arrays. Take a look:
Scala1@main def run: Unit = 2 val chessboard = Array( 3 Array("R", "N", "B", "Q", "K", "B", "N", "R"), // Each inner array represents a row on the chessboard 4 Array("P", "P", "P", "P", "P", "P", "P", "P"), 5 Array("", "", "", "", "", "", "", ""), 6 // ... 7 ) // End of the outer array 8 9 // Access and print first two rows of the chessboard 10 println("Row 1: " + chessboard(0).mkString(", ")) // Outputs: Row 1: R, N, B, Q, K, B, N, R 11 println("Row 2: " + chessboard(1).mkString(", ")) // Outputs: Row 2: P, P, P, P, P, P, P, P
In our chessboard array abstraction, each row represents an inner array, whose elements we can access using two indices.
Let's use our chessboard analogy to fetch a piece from a specific spot:
Scala1@main def run: Unit = 2 val chessboard = Array( 3 Array("R", "N", "B", "Q", "K", "B", "N", "R"), 4 Array("P", "P", "P", "P", "P", "P", "P", "P"), 5 Array("", "", "", "", "", "", "", ""), 6 // ... 7 ) 8 9 val piece = chessboard(0)(2) // Access 3rd piece at the first row 10 println(piece) // Outputs: B
In the above example, piece holds "B" (representing a bishop in chess) positioned at the location (0, 2).
As mentioned in the previous lesson, the Array type in Scala is mutable, allowing for the modification of elements. Here's how to do this:
Scala1@main def run: Unit = 2 val chessboard = Array( 3 Array("R", "N", "B", "Q", "K", "B", "N", "R"), 4 Array("P", "P", "P", "P", "P", "P", "P", "P"), 5 Array("", "", "", "", "", "", "", ""), 6 // ... 7 ) 8 9 chessboard(1)(4) = "" // Make the initial spot of a pawn empty 10 chessboard(0)(4) = "P" // Move pawn one square backwards 11 12 println("Row 1: " + chessboard(0).mkString(", ")) // Outputs: Row 1: R, N, B, Q, P, B, N, R 13 println("Row 2: " + chessboard(1).mkString(", ")) // Outputs: Row 2: P, P, P, P, , P, P, P
It's worth noting in Scala, if you need to modify the size, you can use the List type, which provides more flexibility.
Well done on your first exploration with multidimensional arrays in Scala! We've grasped their structure, created a chessboard paradigm for the arrays, accessed a chess piece, and made a chess move. Essentially, we've learned to create, access, and modify multidimensional arrays. Are you ready for practice exercises to reinforce these newfound skills? Let's jump in! Happy coding!