Four ways to traverse a map

1  Public Static voidMain (string[] args) {2 3 4map<string, string> map =NewHashmap<string, string>();5Map.put ("1", "value1");6Map.put ("2", "value2");7Map.put ("3", "Value3");8   9   //The first type: Universal use, two-time valueTenSystem.out.println ("Traverse key and value through Map.keyset:"); One    for(String key:map.keySet ()) { ASystem.out.println ("key=" + key + "and value=" +Map.get (key)); -   } -    the   //The second Kind -System.out.println ("Using Iterator to traverse key and value through Map.entryset":); -Iterator<map.entry<string, string>> it =Map.entryset (). iterator (); -    while(It.hasnext ()) { +map.entry<string, string> Entry =It.next (); -System.out.println ("key=" + entry.getkey () + "and value=" +Entry.getvalue ()); +   } A    at   //the third type: recommended, especially when the capacity is large -System.out.println ("Traverse key and value through Map.entryset"); -    for(Map.entry<string, string>Entry:map.entrySet ()) { -System.out.println ("key=" + entry.getkey () + "and value=" +Entry.getvalue ()); -   } -  in   //Fourth Type -System.out.println ("Traverse all value through Map.values (), but cannot traverse key"); to    for(String v:map.values ()) { +System.out.println ("value=" +v); -   } the}

Four ways to traverse a map