Java Basic Knowledge Hardening Collection Framework note 55:map Collection HashMap collection (hashmap<integer,string>) case

1. HashMap collection (The key is an Integer, the value is a case of String )

2. code example:

1  Packagecn.itcast_02;2 3 ImportJava.util.HashMap;4 ImportJava.util.Set;5 6 /*7 * hashmap<integer,string>8 * Key: Integer9 * Value: StringTen  */ One  Public classHashMapDemo2 { A      Public Static voidMain (string[] args) { -         //To create a collection object -Hashmap<integer, string> HM =NewHashmap<integer, string>(); the  -         //creating elements and adding elements -         //integer i = new integer; -         //Integer i =; +         //String s = "Brigitte"; -         //Hm.put (i, s); +  AHm.put (27, "Brigitte"); atHm.put (30, "Wind Qing"); -Hm.put (28, "Elina"); -Hm.put (29, "Brigitte"); -  -         //the following notation is octal, but cannot appear with more than 8 of individual data -         //hm.put (003, "Hello"); in         //Hm.put (006, "Hello"); -         //hm.put (007, "Hello"); to         //hm.put (008, "Hello"); +  -         //Traverse theSet<integer> set =Hm.keyset (); *          for(Integer key:set) { $String value =Hm.get (key);Panax NotoginsengSYSTEM.OUT.PRINTLN (key + "---" +value); -         } the  +         //The following method is simply a string representation of the elements of the collection A         //System.out.println ("HM:" + HM); the     } +}

Run the results as follows:

Java Basic Knowledge Hardening Collection Framework note 55:map Collection HashMap collection (hashmap<integer,string>) case