Sams Teach Yourself Java™ in 24 Hours, Sixth Edition

Multidimensional Arrays

The arrays thus far in the hour all have one dimension, so you can retrieve an element using a single number. Some types of information require more dimensions to store adequately as arrays, such as points in an (x,y) coordinate system. One dimension of the array could store the x coordinate, and the other dimension could store the y coordinate.

To create an array that has two dimensions, you must use an additional set of square brackets when creating and using the array, as in these statements:

boolean[][] selectedPoint = new boolean[50][50];selectedPoint[4][13] = true;selectedPoint[7][6] = true;selectedPoint[11][22] = true;

This example creates an array of Boolean values called selectedPoint. The array has 50 elements ...