数组动态初始化

 

==============================练习一======================== 

/*
数组
*/
class LianXi{
 public static void main(String [] args){
  int [] arr =new int[3] ;
  System.out.println(arr);
  System.out.println(arr[0]);
  System.out.println(arr[1]);
  System.out.println(arr[2]);
 }
} 
结果：
[I@e6f7d2
0
0
0
=======================练习二===========================
/*
数组 赋值
*/
class LianXi{
 public static void main(String [] args){
  int [] arr =new int[3] ;
  arr[0] = 10;
  System.out.println(arr);
  System.out.println(arr[0]);
  System.out.println(arr[1]);
  System.out.println(arr[2]);
  System.out.println("============");
  int [] arr1 = arr;
  arr1[2] =20;
  System.out.println("arr = "+arr);
  System.out.println("arr[0] = "+arr[0]);
  System.out.println("arr[1] = "+arr[1]);
  System.out.println("arr[2] = "+arr[2]);
  System.out.println("============");
  System.out.println("arr1 = "+arr1);
  System.out.println("arr1[0] = "+arr1[0]);
  System.out.println("arr1[1] = "+arr1[1]);
  System.out.println("arr1[2] = "+arr1[2]);
 }
} 
结果：
[I@55e55f
10
0
0
============
arr = [I@55e55f
arr[0] = 10
arr[1] = 0
arr[2] = 20
============
arr1 = [I@55e55f
arr1[0] = 10
arr1[1] = 0
arr1[2] = 20