1 public class StringT
 2 {
 3     @org.junit.Test
 4    public void Test(){
 5        StringT test=new StringT();
 6 //       test.length();
 7 //       test.isemptyTest();
 8 //       test.charAtTest();
 9 //       test.codePointAtTest();
10 //       test.equalsIgnoreCaseTest();
11 //       test.startsWithTest();
12 //       test.hashCodeTest();
13        test.indexOfTest();
14    }
15     /**
16      * String有length()方法
17      * 没有length属性
18      */
19     public void length(){
20         String str="dajiahao";
21         System.out.println(str.length());
22         //8
23     }
24     public void isemptyTest(){
25         String str="";
26         String str1="  ";
27         String str2="dajiahao";
28         System.out.println(str.isEmpty());
29         System.out.println(str1.isEmpty());
30         System.out.println(str1.trim().isEmpty());
31         System.out.println(str2.isEmpty());
32 //        true
33 //        false
34 //        true
35 //        false
36     }
37     public void charAtTest(){
38         String str="dajiahao";
39         System.out.println(str.charAt(0));
40         //d
41     }
42     /**
43      * 输出值为Unicode 代码点
44      */
45     public void codePointAtTest(){
46         String str="dajiahao";
47         System.out.println(str.codePointAt(0));
48         System.out.println(str.codePointAt(1));
49         System.out.println(str.codePointAt(2));
50 //        100
51 //        97
52 //        106
53     }
54     public void equalsIgnoreCaseTest(){
55         String str="dajiahao";
56         String str1="dAjiAhaO";
57         System.out.println(str.equalsIgnoreCase(str1));
58 //        true
59     }
60     public void startsWithTest(){
61         String str="dajiahao";
62         System.out.println(str.startsWith("da"));
63         System.out.println(str.startsWith("jia", 2));
64         System.out.println(str.endsWith("hao"));
65 //        true
66 //        true
67 //        true
68     }
69     public void hashCodeTest(){
70         String str="dajiahao";
71         System.out.println(str.hashCode());
72 //        1510538001
73 //        在Java中，哈希码代表对象的特征
74     }
75     public void indexOfTest(){
76         String str="dajiahao,shide";
77         System.out.println(str.indexOf(","));
78         System.out.println(str.indexOf(100));
79 //        8
80 //        0
81     }
82
83
84
85
86 }