import java.util.Collections; import java.util.Hashtable; import java.util.Map; public class Demo { public static void main(String[] s) { Hashtable<String, String>hash = new Hashtable<String, String>(); hash.put("1", "A"); hash.put("2", "B"); hash.put("3", "C"); hash.put("4", "D"); hash.put("5", "E"); hash.put("6", "F"); hash.put("7", "G"); hash.put("8", "H"); hash.put("9", "I"); hash.put("10", "J"); System.out.println("Hashtable = " + hash); Map<String, String>m = Collections.unmodifiableMap(hash); System.out.println("Hashtable is now read-only!"); } }
import java.util.Arrays; import java.util.HashSet; import java.util.Set; public class Demo { public static void main(String[] a) { Integer arr[] = { 50, 100, 150, 200, 250, 300 }; Set<Integer>set = new HashSet<Integer>(Arrays.asList(arr)); System.out.println(set.contains(200)); System.out.println(set.contains(150)); System.out.println(set.contains(100)); System.out.println(set.contains(10)); } }
import java.util.Iterator; import java.util.SortedSet; import java.util.TreeSet; public class Demo { public static void main(String[] argv) throws Exception { SortedSet<String> set = new TreeSet<String>(); set.add("T"); set.add("R"); set.add("S"); set.add("Q"); set.add("V"); set.add("U"); set.add("W"); Iterator<String> i = set.iterator(); System.out.println("SortedSet elements..."); while (i.hasNext()) { Object ob = i.next(); System.out.println(ob.toString()); } set.add("Z"); set.add("Y"); i = set.iterator(); System.out.println("Updated SortedSet elements..."); while (i.hasNext()) { Object ob = i.next(); System.out.println(ob.toString()); } } }
import java.util.SortedMap; import java.util.TreeMap; public class Demo { public static void main(String[] args) { TreeMap<String, String>tMap = new TreeMap<String, String>(); tMap.put("1", "A"); tMap.put("2", "B"); tMap.put("3", "C"); tMap.put("4", "D"); tMap.put("5", "E"); tMap.put("6", "F"); tMap.put("7", "G"); tMap.put("8", "H"); tMap.put("9", "I"); tMap.put("10", "J"); SortedMap<String, String>map = tMap.subMap("3", "7"); System.out.println("SortedMap = " + map); map = tMap.subMap("5", "7"); System.out.println("SortedMap = " + map); map = tMap.subMap("8", "8"); System.out.println("SortedMap = " + map); } }
import java.util.HashMap; import java.util.Map; import java.util.TreeMap; public class Demo { public static void main(String[] args) { HashMap<String, String>map = new HashMap<String, String>(); map.put("1", "A"); map.put("6", "B"); map.put("3", "C"); map.put("7", "D"); map.put("5", "E"); map.put("2", "F"); map.put("4", "G"); map.put("8", "H"); Map<String, String>tMap = new TreeMap<String, String>(map); System.out.println("Sorted Map values: "+tMap); } }
import java.util.HashMap; import java.util.Map; import java.util.TreeMap; public class Demo { public static void main(String[] a) { Map<String, String>map = new HashMap<String, String>(); map.put("1", "A"); map.put("2", "B"); map.put("3", "C"); map.put("4", "D"); map.put("5", "E"); map.put("6", "F"); map.put("7", "G"); map.put("8", "H"); map.put("9", "I"); Map<String, String>sorted = new TreeMap<String, String>(map); System.out.println("Sorted Map = "+sorted); } }
import java.util.Collections; import java.util.HashMap; import java.util.Map; public class Demo { public static void main(String[] argv) throws Exception { Map<String, String>map = new HashMap<String,String>(); map.put("1","A"); map.put("2","B"); map.put("3","C"); // making it read-only map = Collections.unmodifiableMap(map); try { map.put("4","D"); map.put("5","E"); map.put("6","F"); } catch (UnsupportedOperationException e) { System.out.println(e.getMessage()); } } }
import java.util.HashMap; import java.util.Map; public class Demo { public static final void main(String[] args) { Map<String,String>map = new HashMap<>(); map.put("Football", "A"); map.put("Squash", "B"); map.put("Cricket", "C"); map.put("Hockey", "D"); map.put("Rugby", "E"); map.put("Golf", "F"); map.put("Archery", "G"); System.out.println("Size of HashMap = " + map.size()); map.put(null, "H"); System.out.println("Updated Size of HashMap = " + map.size()); System.out.println("For null = " + map.get(null)); } }
import java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; public class Demo { public static void main(String[] args) { Map<String, String>map = new LinkedHashMap<>(); map.put("Jack","0"); map.put("Tim", "1"); map.put("David","2"); map.put("Tom", "3"); map.put("Kevin", "4"); map.put("Jeff", "5"); map.put("Katie","6"); map.put("Steve", "7"); map.put("Andrew", "8"); map.put("Angelina", "9"); String str = (String) map.get("David"); System.out.println("Rank of David = " + str); Iterator iterator = map.keySet().iterator(); while (iterator.hasNext()) { String resKey = (String) iterator.next(); System.out.println("Rank of " + resKey + " is " + map.get(resKey)); } } }
import java.util.LinkedHashMap; import java.util.Map; public class Demo { public static void main(String[] args) { Map<String, Integer>map = new LinkedHashMap<>(); map.put("Jack", 0); map.put("Tim", 1); map.put("David", 2); map.put("Tom", 3); map.put("Kevin", 4); map.put("Jeff", 5); map.put("Katies", 6); map.put("Steve", 7); map.put("Andrew", 8); map.put("Angelina", 9); for (Map.Entry<String, Integer>entry: map.entrySet()) { System.out.println(entry.getKey() + " => " + entry.getValue()); } } }
We use cookies to provide and improve our services. By using our site, you consent to our Cookies Policy. Accept Learn more