//: c04:MultiDimArray.java // Creating multidimensional arrays. // From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002 // www.BruceEckel.com. See copyright notice in CopyRight.txt. import com.bruceeckel.simpletest.*; import java.util.*; public class MultiDimArray { static Test monitor = new Test(); static Random rand = new Random(); public static void main(String[] args) { int[][] a1 = { { 1, 2, 3, }, { 4, 5, 6, }, }; for(int i = 0; i < a1.length; i++) for(int j = 0; j < a1[i].length; j++) System.out.println( "a1[" + i + "][" + j + "] = " + a1[i][j]); // 3-D array with fixed length: int[][][] a2 = new int[2][2][4]; for(int i = 0; i < a2.length; i++) for(int j = 0; j < a2[i].length; j++) for(int k = 0; k < a2[i][j].length; k++) System.out.println("a2[" + i + "][" + j + "][" + k + "] = " + a2[i][j][k]); // 3-D array with varied-length vectors: int[][][] a3 = new int[rand.nextInt(7)][][]; for(int i = 0; i < a3.length; i++) { a3[i] = new int[rand.nextInt(5)][]; for(int j = 0; j < a3[i].length; j++) a3[i][j] = new int[rand.nextInt(5)]; } for(int i = 0; i < a3.length; i++) for(int j = 0; j < a3[i].length; j++) for(int k = 0; k < a3[i][j].length; k++) System.out.println("a3[" + i + "][" + j + "][" + k + "] = " + a3[i][j][k]); // Array of nonprimitive objects: Integer[][] a4 = { { new Integer(1), new Integer(2)}, { new Integer(3), new Integer(4)}, { new Integer(5), new Integer(6)}, }; for(int i = 0; i < a4.length; i++) for(int j = 0; j < a4[i].length; j++) System.out.println("a4[" + i + "][" + j + "] = " + a4[i][j]); Integer[][] a5; a5 = new Integer[3][]; for(int i = 0; i < a5.length; i++) { a5[i] = new Integer[3]; for(int j = 0; j < a5[i].length; j++) a5[i][j] = new Integer(i * j); } for(int i = 0; i < a5.length; i++) for(int j = 0; j < a5[i].length; j++) System.out.println("a5[" + i + "][" + j + "] = " + a5[i][j]); // Output test int ln = 0; for(int i = 0; i < a3.length; i++) for(int j = 0; j < a3[i].length; j++) for(int k = 0; k < a3[i][j].length; k++) ln++; monitor.expect(new Object[] { "a1[0][0] = 1", "a1[0][1] = 2", "a1[0][2] = 3", "a1[1][0] = 4", "a1[1][1] = 5", "a1[1][2] = 6", new TestExpression( "%% a2\\[\\d\\]\\[\\d\\]\\[\\d\\] = 0", 16), new TestExpression( "%% a3\\[\\d\\]\\[\\d\\]\\[\\d\\] = 0", ln), "a4[0][0] = 1", "a4[0][1] = 2", "a4[1][0] = 3", "a4[1][1] = 4", "a4[2][0] = 5", "a4[2][1] = 6", "a5[0][0] = 0", "a5[0][1] = 0", "a5[0][2] = 0", "a5[1][0] = 0", "a5[1][1] = 1", "a5[1][2] = 2", "a5[2][0] = 0", "a5[2][1] = 2", "a5[2][2] = 4" }); } } ///:~