Collections is a structure that gives an outline to store and control the social occasion of things. Each one of the operations that you perform on a data, for instance, looking for, sorting, consideration, control, deletion thus on can be performed by Java Collections. Taking after is the grammar revelation for java.util.Collections class. [java] public class Collections extends Object [/java] Following are the fields of java.util.Collections class.

The following is the conceptual figure for java.util Collections class. The java.lang.Interfaces package will provide various interfaces to support lang classes. The java.lang.Object class is the root class for every java classes.

Following are the regular methods for java.util Collections Class.

Following is the syntax declaration. [java]public static <T> boolean addAll(Collection<? super T> c, T.. a) [/java] Where c is the collection and a is the element to inserted. DemoCollection.java [java] package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create array list object List arrlist = new ArrayList(); // populate the list arrlist.add("S"); arrlist.add("A"); arrlist.add("I"); System.out.println("Initial collection value: "+arrlist); // add values to this collection boolean b = Collections.addAll(arrlist, "1","2","3"); System.out.println("Final collection value: "+arrlist); } } [/java] Here the developer added three elements by using the ArrayList() method. Output:Now compile the code result will be as follows. [java] Initial collection value: [S, A, I] Final collection value: [S, A, I, 1, 2, 3] [/java]

Following is the syntax declaration of the method. [java]public static <T> Queue<T> asLifoQueue(Deque<T> deque)[/java] DemoCollection.java [java]package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create Deque object Deque<Integer> deque = new ArrayDeque<Integer>(7); // populate the object deque.add(8); deque.add(9); deque.add(10); deque.add(11); deque.add(12); deque.add(13); deque.add(14); // get queue from the deque Queue nq = Collections.asLifoQueue(deque); System.out.println("View of the queue is: "+nq); } } [/java] The java.util.Collections.asLifoQueue() method follows Last-In-First-Out concept. Output:Now compile the code result will be as follows. [java]View of the queue is: [8, 9, 10, 11, 12, 13, 14][/java]

Following is the syntax declaration of the method. [java]public static <T> int binarySearch(List<? extends Comparable<? super T>> list, T key)[/java] DemoCollection.java [java]package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create arraylist ArrayList<String> arlst=new ArrayList<String>(); // populate the list arlst.add("StackOverFlow"); arlst.add("Dice"); arlst.add("SPlessons"); arlst.add("TUTORIALS"); // search the list for key 'QUALITY' int index=Collections.binarySearch(arlst, "SPlessons"); System.out.println("'SPlessons' is available at index: "+index); } } [/java] Here the developer created the ArrayList to store the strings and given four strings to search. Output:Now compile the code result will be as follows. [java] 'SPlessons' is available at index: 2 [/java]

Following is the syntax declaration of the method. [java]public static <E> List<E> checkedList(List<E> list,Class<E> type)[/java] DemoCollection.java [java] package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create arraylist ArrayList<String> arlst=new ArrayList<String>(); // populate the list arlst.add("StackOverFlow"); arlst.add("Dice"); arlst.add("SPlessons"); arlst.add("TUTORIALS"); // create typesafe view of the list Collection<String> tslst; tslst = Collections.checkedList(arlst,String.class); System.out.println("Dynamically typesafe view is: "+tslst); } } [/java] The java.util.Collections.checkedList() method is used to return a dynamically typesafe perspective view of the list. Output:Now compile the code result will be as follows. [java] Dynamically typesafe view is: [StackOverFlow, Dice, SPlessons, TUTORIALS] [/java]

Following is the syntax declaration of the method. [java]public static <K,V> SortedMap<K,V> checkedSortedMap(SortedMap<K,V> m,Class<K> keyType,Class<V> valueType)[/java] Where m is the guide for which a powerfully typesafe view is to be returned. DemoCollection.java [java]package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create sorted map SortedMap smap = new TreeMap(); // populate the map smap.put("1", "WWW."); smap.put("2", "SPLESSONS"); smap.put("3", ".COM"); // get typesafe view of the sorted map SortedMap tsmap; tsmap = Collections.checkedSortedMap(smap,String.class,String.class); System.out.println("Typesafe view of the sorted map: "+tsmap); } } [/java] Output:Now compile the code result will be as follows. [java] Typesafe view of the sorted map: {1=WWW., 2=SPLESSONS, 3=.COM} [/java]

Following is the syntax declaration of the method. [java]public static <T> Enumeration<T> enumeration(Collection<T> c)[/java] Where c is the collection. DemoCollection.java [java] package com.SPlessons; import java.util.*; public class DemoCollection { public static void main(String args[]) { // create array list object List arrlist = new ArrayList(); // populate the list arrlist.add("S"); arrlist.add("P"); arrlist.add("L"); arrlist.add("E"); arrlist.add("S"); arrlist.add("S"); arrlist.add("O"); arrlist.add("N"); // create Enumeration Enumeration e = Collections.enumeration(arrlist); System.out.println("Print the enumeration"); while(e.hasMoreElements()){ System.out.println("Value is: "+e.nextElement()); } } } [/java] Enum in java is an information sort that contains settled arrangement of constants. It can be utilized for a considerable length of time of the week, bearings and so on. Output:Now compile the code result will be as follows. [java] Print the enumeration Value is: S Value is: P Value is: L Value is: E Value is: S Value is: S Value is: O Value is: N [/java]

• Java.util Collections - The java.util.Collections.max() technique is used to give back the most outrageous segment of the given collection.
• The java.util.Collections.min() strategy is used to give back the base segment of the given collection.