Precautions for using Arrays. asList

1. Blog category:
2 java Integration
3. data structures and algorithms
4
5 Arrays. asList
6
7. Check the following code:
8. Add Java code to favorites
9
10 import java. util. Arrays;
11 import java. util. List;
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14 public class TestAsList {
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16 public static void main (String [] args ){
17 String [] str = new String [] {"1", "2", "3 "};
18 List <String> list = Arrays. asList (str );
19 list. add ("4 ");
20}
21}
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23
24
25 you guess, is there a problem?
26
27. Run the program and report a future error:
28 Java code favorites code
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30 Exception in thread "main" java. lang. UnsupportedOperationException
31 at java. util. AbstractList. add (AbstractList. java: 131)
32 at java. util. AbstractList. add (AbstractList. java: 91)
33 at test. TestAsList. main (TestAsList. java: 12)
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37 Cause Analysis:
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39 The value of list is transmitted from data, so the length of list is fixed. An error occurred while running the program to list. add ("4.
40
41. solution:
42 Java code collection code
43
44 import java. util. ArrayList;
45 import java. util. Arrays;
46 import java. util. List;
47
48
49 public class TestAsList {
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51 public static void main (String [] args ){
52 String [] str = new String [] {"1", "2", "3 "};
53 List <String> list = new ArrayList <String> (Arrays. asList (str ));
54 list. add ("4 ");
55 System. out. println (list. size ());
56}
57}
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59
60
61. Conclusion: Pay attention when using asList.