If we want to represent a group of object as key-value pairs. then we have to use MAP. Key-value pairs means, for every value there will be a unique key. MAP MAP Features Both keys and values are objects only. Duplicate keys are not allowed, but duplicate values are allowed. Each key-value pair is called Entry, …
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Let us take some programming examples based on String objects in TreeSet concept : Example1 : Write a JAVA Program to insert String Objects into a TreeSet where all elements should be inserted according to reverse of alphabetical order. import java.util.*; class myComp implements Comparator // Our custom comparator class { public int compare(Object obj1, Object …
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Being a child Interface of Collection Interface, we will use Set when we want to represent a group of individual objects as a single entity, where no duplicate elements are allowed and insertion order is not preserved. Being a child interface of Collection Interface, all methods declared in Collection Interface are by-default available in Set (Interface). …
Set Interface in Java – HashSet , SortedSet Interface , LinkedHashSet Read More »
The 3 CURSORS OF JAVA: We use cursors when we want to get objects from a Collection one by one. There are 3 cursors in JAVA : Enumeration Iterator ListIterator Let’s discuss these cursors one by one : Enumeration in Java We can use Enumeration to get objects one by one from legacy collection object. To …
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List Interface is a child interface of Collection Interface. We will go for List Interface if we want to represent a group of individual objects as a single entity where duplicates are allowed and the insertion order must be preserved. Say, the above list (may be ArrayList or LinkedList) contains 6 elements, the elements in …
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