Map Interface
Examples of Map methods
ImportJava.util.*; Public classTESTMAP2 { Public Static voidMain (String args[]) {Map<string, integer> m1 =NewHashmap<string, integer>(); M1.put ("One", 1); M1.put ("Both", 2); M1.put ("Three", 3); System.out.println (M1.size ()); System.out.println (M1.containskey ("One")); if(M1.containskey ("the")) { //int i = ((Integer) m1.get ("II")). Intvalue (); inti = M1.get ("II")); System.out.println (i); } }}
Testmap2.java
ImportJava.util.*; Public classTestargswords {//private static final integer one = new integer (1); Private Static Final intone = 1; Public Static voidMain (String args[]) {Map m=NewHashMap (); for(inti = 0; i < args.length; i++) { //integer freq = (integer) m.get (Args[i]); intFreq = (Integer) m.get (args[i]) = =NULL? 0: (Integer) M.get (Args[i]); //M.put (Args[i], (freq = = null?) One:new Integer (Freq.intvalue () + 1 ));M.put (Args[i], freq==0? One:freq + 1); } System.out.println (M.size ()+ "Distinct words detected:"); System.out.println (m); }}
TestargswordsJDK1.5 generics
ImportJava.util.*; Public classBasicgeneric { Public Static voidMain (string[] args) {List<String> C =NewArraylist<string>(); C.add ("AAA"); C.add ("BBB"); C.add ("CCC"); for(inti=0; I<c.size (); i++) {String s=C.get (i); System.out.println (s); } Collection<String> C2 =NewHashset<string>(); C2.add ("AAA"); C2.add ("BBB"); C2.add ("CCC"); for(Iterator<string> it =c2.iterator (); It.hasnext ();) {String s=It.next (); System.out.println (s); } }}classMyNameImplementsComparable<myname> { intAge ; Public intcompareTo (MyName mn) {if( This. Age > Mn.age)return1; Else if( This. Age < Mn.age)return-1; Else return0; }}
Basicgeneric.java
ImportJava.util.*; Public classTestArgsWords2 {Private Static Final intone = 1; Public Static voidMain (String args[]) {Map<string, integer> m =NewHashmap<string, integer>(); for(inti = 0; i < args.length; i++) { if(!M.containskey (Args[i])) {M.put (args[i], one); } Else { intFreq =M.get (Args[i]); M.put (Args[i], freq+ 1); }} System.out.println (M.size ()+ "Distinct words detected:"); System.out.println (m); }}
Testargswords2.javaSummary
J2SE Container _map Interface _ generic type