1  public static void main(String[] args)
 2       {
 3           int[] arry = new int[4];         //int 默认值0   //浮点型 0.0
 4           for(int i =0; i < arry.length;i++)
 5           {
 6               System.out.println(arry[i]);
 7           }
 8           
 9           System.out.println("-----------");
10           char[] arr1 = new char[5];       //默认值是 0 ascall码0
11           int i =0;
12           for( i =0; i <arr1.length;i++)
13           {
14               System.out.println("------"+arr1[i]+"-------");
15           }
16           
17           if(arr1[0]==0)
18           {
19               System.out.println("你好");
20           }
21           
22           boolean[] arr4 = new boolean[5];
23           System.out.println(arr4[0]);   //默认值是false
24           
25           String[] arr5 = new String[5];
26           
27           System.out.println(arr5[0]);   // 引用数据类型 默认值是 null 没有赋值
28           
29           if(arr5[0]== null)
30           {
31               System.out.println("zhenglei");
32           }
33           
34       }