1    /* 
2        * A program to perform some basic operations on a list of String names. 
3        */
4        package arraylists;
5    
6                import javax.sound.midi.Soundbank;
7       import java.util.ArrayList;
8        import java.util.List;
9        import java.util.stream.Collectors;
10   
11              public class ArrayListProcessing {
12   
13                  public static void main(String[] args){
14                      // POINT A: Add some strings which represent names to an ArrayList.
15                      List<String> names = new ArrayList<>();
16                      names.add("Holiday, Billie");
17                      names.add("Claudel, Camille");
18                      names.add("Picasso, Pablo");
19                      names.add("Gallen-Kallela, Akseli");
20                      names.add("Zotto, Osvaldo");
21   
22                      // POINT B: Create an ArrayList of just the first names of the names
23                      //          ArrayList. Use a for loop to print out the names, separated
24                      //          by spaces.
25   
26                      List<String> firstNamesList = names.stream()
27                              .map(n -> firstName(n))
28                             .collect(Collectors.toList());
29   
30                      System.out.print("First names: ");
31                      for(String firstName : firstNamesList){
32                              System.out.print(firstName + " ");
33                          }
34                     System.out.println();
35   
36                     // POINT C: Use String’s join function to create and print a String of
37                      //          just the first names of the names ArrayList with each
38                      //          name separated by a comma.
39                     String firstNames = names.stream()
40                              .map(n -> firstName(n))
41                              .collect(Collectors.joining(", "));
42   
43                      System.out.println("First names: " + firstNames);
44   
45                      // POINT D: By analogy from points B and C, print a comma-separated
46                     // list of the last names in the names ArrayList.
47                     List<String> lastNamesList = names.stream()
48                              .map(n -> lastName(n))
49                              .collect(Collectors.toList());
50   
51                      System.out.print("Last names: ");
52                      for(String lastName : lastNamesList){
53                             System.out.print(lastName + " ");
54                        }
55   
56                     // POINT E: Print a comma-separated list of all uppercase first names
57                     //          from the list of names in the names ArrayList.
58                      String upperCaseFirstNames = names.stream()
59                              .map(n -> firstName(n))
60                              .map(n -> n.toUpperCase())
61                             .collect(Collectors.joining(", "));
62   
63                     System.out.println("Uppercase first names: " + upperCaseFirstNames);
64   
65                      // POINT F: Print a comma-separated list of all hyphenated last names
66                      //          from the list of names in the names ArrayList.
67                     String hyphenatedLastNames = names.stream()
68                             .map(n -> lastName(n))
69                             .filter(n -> n.contains("-"))
70                              .collect(Collectors.joining(", "));
71   
72                      System.out.println("Hyphenated last names: " + hyphenatedLastNames);
73   
74                      // POINT G: Print the integer value of the total length of all names
75                      //          in the names ArrayList.
76                      int totalLength = names.stream()
77                              .map(n -> n.length())
78                             .reduce(0, (n1,n2) -> n1 + n2);
79                     System.out.println("Total length: " + totalLength);
80   
81                     // POINT H: Print the integer value of the total length of all
82                     //          first names in the names ArrayList.
83                      int firstLength = names.stream()
84                              .map(n -> firstName(n))
85                              .map(n -> n.length())
86                             .reduce(0, (n1,n2) -> n1 + n2);
87                      System.out.println("First name length: " + firstLength);
88   
89   
90                      // POINT I: Print the integer value of the product of the length of
91                      //          all first names in the names ArrayList.
92                     int first1Length = names.stream()
93                              .map(n -> firstName(n))
94                              .map(n -> n.length())
95                              .reduce( 1, (n1,n2) -> n1 *n2);
96                      System.out.println("First name product length: "+first1Length);
97                  }
98          private static String firstName(String directoryStyleName) {
99                      return directoryStyleName.substring(0,directoryStyleName.indexOf(","));
100                }
101        private static String lastName(String directoryStyleName) {
102                    return directoryStyleName.substring(directoryStyleName.indexOf(" "));
103               }
104  }
105  
106  
107