What the classroom says: set and map

Set-related knowledge:

1  PackageOrg.hanqi.array;2 3 ImportJava.util.*;4 5  Public classTest2 {6 7      Public Static voidMain (string[] args) {8         9 //int i;//default I=0Ten //int [] m = new int[5];//assigned a value of 5 a 0 One          A         //Hash -set<string> s =NewHashset<string>(); -hashset<string> S1 =NewHashset<string>(); the          -         if(S.add ("a")) -         { -System.out.println ("Save a Success"); +         }         -S.add ("B"); +S.add ("C"); AS.add ("D"); atS.add ("E"); -S.add ("F"); -S.add ("G"); -          -         if(!s.add ("a")) -         { inSystem.out.println ("Save a Failed"); -         } to         //S.add ("a"); +         //S.add ("a"); -          the          for(String t:s) *         { $ System.out.print (t);Panax Notoginseng         } -          the System.out.println (); +          ASystem.out.println ("s size=" +s.size ()); the  +         if(S.remove ("D")) -         { $System.out.println ("Removal succeeded"); $         } -         Else -         { theSystem.out.println ("Removal failed"); -         }Wuyi          theSystem.out.println ("s size=" +s.size ()); -          Wu         //iterators -Iterator<string> it =s.iterator (); About          while(It.hasnext ()) $         { -String T =It.next (); -             if(T.equals ("C")) -             { A It.remove (); +             } the             Else -             { $ System.out.print (t); the             } the              the         } the          - System.out.println (); in          theSystem.out.println ("s size=" +s.size ()); the          AboutSystem.out.println ("TreeSet"); the          theset<string> s2 =NewTreeset<string>();  the          +S2.add ("F"); -S2.add ("B"); theS2.add ("D");BayiS2.add ("C"); theS2.add ("E"); theS2.add ("a"); -S2.add ("G"); -                          the          for(String t:s2) the         { the System.out.print (t); the         } -          the System.out.println (); the          theSystem.out.println ("S2 's size=" +s2.size ());94     } the}

The result of the operation is:

Map Related knowledge:

1  PackageOrg.hanqi.array;2 3 ImportJava.util.*;4 5  Public classTest3 {6 7      Public Static voidMain (string[] args) {8         9map<string,string> m =NewHashmap<string,string>();Ten          OneM.put ("7", "Zibo"); AM.put ("9", "Jinan"); -M.put ("5", "Qingdao"); -M.put ("1", "Qingdao"); theM.put ("8", "Qingdao"); -M.put ("6", "Qingdao"); -M.put ("3", "Qingdao"); -M.put ("2", "Qingdao"); +M.put ("0", "Qingdao");  -         //length +System.out.println ("length =" +m.size ()); AM.put ("0534", "Qingdao"); atM.put (NULL,NULL); -System.out.println ("length =" +m.size ()); -         //get value based on key -System.out.println ("0533=" +m.get ("0533")); -         //if key exists -         if(M.containskey ("0533")) in         { -System.out.println ("Key 0533 already exists"); to         } +         //value is present -         if(M.containsvalue ("Zibo")) the         { *System.out.println ("Value Zibo already exists"); $         }Panax Notoginseng         //Traverse -          for(String k:m.keyset ()) the         { +System.out.println (k + "=" +M.get (k)); A         } the     } +}

The result of the operation is:

Related Mind Mapping:

Classroom-Organized: set and map