Java连载68-数组的拷贝、二维数组

package com.bjpowernode.java_learning;

​

public class D68_1_CopyOfArrays {

  public static void main(String[] args) {

    int[] a1 = {2,3,4,5,6,7,8};

    int[] a2 = {10,11,12,13,14,15,16};

    System.arraycopy(a1,2,a2,3,3);

    for(int i=0;i<a2.length;i++) {

      System.out.println(a2[i]);

    }

  }

}

 

package com.bjpowernode.java_learning;

​

public class D68_2_TwoDimetionArrays {

  public static void main(String[] args) {

    int[][] a = {{1,2,3},{4,5,6},{7,8,9,10}};

    //以上这个数组有多少个一维数组

    System.out.println(a.length+"个一维数组");

    //获取第一个一维数组的第一个元素

    int[] a0 = a[0];

    int a00 = a0[0];

    System.out.println(a00);

    System.out.println(a[0][0]);

    //获取最后一个一维数组的最后一个元素

    System.out.println(a[a.length-1][a[a.length-1].length-1]);

    //遍历二维数组

    System.out.println("=============================");

    for(int i=0;i<a.length;i++) {

      for(int j=0;j<a[i].length;j++) {

        System.out.println(a[i][j]);

      }

    }

  }

​

}

package com.bjpowernode.java_learning;

​

public class D68_3_TwoDimentionInitial {

  public static void main(String[] args) {

    //3个一维数组

    //每个一维数组中有4个元素

    int[][] a = new int[2][2];

    //遍历

    for(int i=0;i<a.length;i++) {

      for(int j=0;j<a[i].length;j++) {

        System.out.println(a[i][j]);

      }

    }

   

    m1(new int[][] {{1,2,3},{4,5,6}});

   

  }

  public static void m1(int[][] a) {

    for(int i=0;i<a.length;i++) {

      for(int j=0;j<a[i].length;j++) {

        System.out.print(a[i][j]+" ");

      }

      System.out.println();

    }

  }

​

}

​