www.pudn.com > TIJc04.rar > MultiDimArray.java

//: 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" 
    }); 
  } 
} ///:~