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Published byAngel Stanley Modified about 1 year ago

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Chapter 7 Multidimensional Arrays

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Defining a two dimensional array elementType[][] arrayName; // Java pro elementType arrayName[][]; // C++ alternate For example: int[][] chessboard; To allocate space for the array, use new: chessboard = new int[8][8]; Or int[][] chessboard = new int[8][8];

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Accessing elements int king = 10; chessboard[0][4] = king; int piece = chessboard[7][3]; Each dimension must use a pair of brackets around the index [] Do not try chessboard[7, 3] notation

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Initializing multiple dimensions

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What’s an array? A two-dimensional array is actually a one- dimensional array where each element is a one-dimensiona array An “array of arrays” is an important concept! Each array has its own length property Array lengths can be different (ragged array)

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The length property in action

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Rectangular versus ragged arrays A rectangular array has the same number of elements in each array for a given dimension int[][] myArray = new int[5][7]; myArray has 5 x 7 = 35 elements, with 7 elements in each of the 5 rows A ragged array has varying numbers of elements in a given dimension, as illustrated on the next slide:

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Ragged array definition

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The contents of a ragged array

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Another array initialization example

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Passing a two-dimensional array as an argument to a method

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Multiple Dimensional Arrays An array of arrays of arrays of…. Each dimension can consist of rectangular or ragged arrays Each dimension is enclosed with a pair of brackets Maximum number of dimensions is nominally 255 for the VM*

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Three-dimensional ragged array

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Lab 2 Write a program to create a chessboard stored as a two-dimensional character array Chess is played on an 8 x 8 square board with a total of 64 squares Empty squares can be represented by a space Abbreviate pieces as ‘R’ = rook, ‘N’ = knight, ‘B’ = Bishop, ‘Q’ = queen, ‘K’ = king, ‘P’ = pawn Initialize the array according to the diagram

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What the array dimensions mean The columns will be the first array dimension Label columns ‘a’ – ‘h’ Column a is the 0 index, h is the 7 index The rows will be the second array dimension Number rows 1-8 Row 1 is the 0 index, 8 is the 7 index

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What to do and turn in Write a method that creates a two- dimensional character array, initializes it with the starting chessboard as shown in the diagram, and returns the array Write a method that prints the chess board contents and the row/column labels Turn in a screen shot of the chess board Turn in a print-out of your program

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What the chessboard looks like:

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Extra Credit (10%) Write a user interface that makes a move The notation is the letter/number of the start location and the letter/number of the end location (e.g. “d1 g4” would move the white queen diagonally 3 squares) Allow any move (don’t check legality) Print an updated view of the board showing the pieces after the move

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