java笔记: array的基本用法

 1 import java.lang.reflect.Array;
 2 import java.util.ArrayList;
 3 import java.util.Arrays;
 4 import java.util.List;
 5 
 6 import org.junit.Test;
 7 
 8 
 9 public class ArrayTest {
10 
11     public static void print(String str) {
12         System.out.print(str);
13     }
14     public static void print(String format, Object... args) {
15         System.out.printf(format, args);
16     }
17     
18     @Test
19     public void Test_Array() {
20         //init
21         int[] values = {1,2,3};
22         Object arr =Array.newInstance(int.class, 10);
23         print("The class of arr is %s\n", arr.getClass().toString());
24         print("The class of values is %s\n", values.getClass().toString());
25         //cast
26         int[] arr2=(int[])arr;
27         //assign  & iterate        
28         values[1] +=2;
29         for (int i : values) {
30             print("content %d\n",i);
31         }
32         //assign and iterate
33         for (int i=0;i<Array.getLength(arr);i++) {
34             Array.setInt(arr, i, i*100);
35             print("Content of Array %d\n" ,Array.getInt(arr, i));
36         }
37         Integer[] refInt=new Integer[10];
38         //array to list
39         List<Integer> lst1=Arrays.asList(refInt);
40         lst1.set(1, 100);
41         //list to array
42         lst1.toArray(refInt);
43         
44     }
45 }