How to use Set?<\/h2>\n\n\n\n In Java, we must import java.util.Set<\/code> package in order to use Set<\/code>.<\/p>\n\n\n\n\/\/ Set implementation using HashSet\nSet<String> animals = new HashSet<>();\n<\/code><\/pre>\n\n\n\nHere, we have created a Set<\/code> called animals<\/var>. We have used the HashSet<\/code> class to implement the Set<\/code> interface.<\/p>\n\n\n\nMethods of Set<\/h2>\n\n\n\n The Set<\/code> interface includes all the methods of the Collection<\/code> interface. It’s because Collection<\/code> is a super interface of Set<\/code>.<\/p>\n\n\n\nSome of the commonly used methods of the Collection<\/code> interface that’s also available in the Set<\/code> interface are:<\/p>\n\n\n\nadd()<\/strong> – adds the specified element to the set<\/li>addAll()<\/strong> – adds all the elements of the specified collection to the set<\/li>iterator()<\/strong> – returns an iterator that can be used to access elements of the set sequentially<\/li>remove()<\/strong> – removes the specified element from the set<\/li>removeAll()<\/strong> – removes all the elements from the set that is present in another specified set<\/li>retainAll()<\/strong> – retains all the elements in the set that are also present in another specified set<\/li>clear()<\/strong> – removes all the elements from the set<\/li>size()<\/strong> – returns the length (number of elements) of the set<\/li>toArray()<\/strong> – returns an array containing all the elements of the set<\/li>contains()<\/strong> – returns true<\/code> if the set contains the specified element<\/li>containsAll()<\/strong> – returns true<\/code> if the set contains all the elements of the specified collection<\/li>hashCode()<\/strong> – returns a hash code value (address of the element in the set)<\/li><\/ul>\n\n\n\n<\/p>\n\n\n\n
Set Operations<\/h2>\n\n\n\n The Java Set<\/code> interface allows us to perform basic mathematical set operations like union, intersection, and subset.<\/p>\n\n\n\nUnion<\/strong> – to get the union of two sets x<\/var> and y<\/var>, we can use x.addAll(y)<\/code><\/li>Intersection<\/strong> – to get the intersection of two sets x<\/var> and y<\/var>, we can use x.retainAll(y)<\/code><\/li>Subset<\/strong> – to check if x<\/var> is a subset of y<\/var>, we can use y.containsAll(x)<\/code><\/li><\/ul>\n\n\n\nImplementation of the Set Interface<\/h2>\n\n\n\n 1. Implementing HashSet Class<\/strong><\/p>\n\n\n\nimport java.util.Set;\nimport java.util.HashSet;\n\nclass Main {\n\n public static void main(String[] args) {\n \/\/ Creating a set using the HashSet class\n Set<Integer> set1 = new HashSet<>();\n\n \/\/ Add elements to the set1\n set1.add(2);\n set1.add(3);\n System.out.println(\"Set1: \" + set1);\n\n \/\/ Creating another set using the HashSet class\n Set<Integer> set2 = new HashSet<>();\n\n \/\/ Add elements\n set2.add(1);\n set2.add(2);\n System.out.println(\"Set2: \" + set2);\n\n \/\/ Union of two sets\n set2.addAll(set1);\n System.out.println(\"Union is: \" + set2);\n }\n}\n<\/code><\/pre>\n\n\n\nOutput<\/strong><\/p>\n\n\n\nSet1: [2, 3]\nSet2: [1, 2]\nUnion is: [1, 2, 3]\n<\/samp><\/code><\/pre>\n\n\n\n<\/p>\n\n\n\n
2. Implementing TreeSet Class<\/strong><\/p>\n\n\n\nimport java.util.Set;\nimport java.util.TreeSet;\nimport java.util.Iterator;\n\nclass Main {\n\n public static void main(String[] args) {\n \/\/ Creating a set using the TreeSet class\n Set<Integer> numbers = new TreeSet<>();\n\n \/\/ Add elements to the set\n numbers.add(2);\n numbers.add(3);\n numbers.add(1);\n System.out.println(\"Set using TreeSet: \" + numbers);\n\n \/\/ Access Elements using iterator()\n System.out.print(\"Accessing elements using iterator(): \");\n Iterator<Integer> iterate = numbers.iterator();\n while(iterate.hasNext()) {\n System.out.print(iterate.next());\n System.out.print(\", \");\n }\n\n }\n}\n<\/code><\/pre>\n\n\n\nOutput<\/strong><\/p>\n\n\n\nSet using TreeSet: [1, 2, 3]\nAccessing elements using iterator(): 1, 2, 3,\n<\/samp><\/code><\/pre>\n\n\n\nTo learn more about\u00a0TreeSet<\/code>, visit\u00a0Java TreeSet.<\/p>\n\n\n\nNow that we know what Set<\/code> is, we will see its implementations in classes like EnumSet<\/code>, HashSet<\/code>, LinkedHashSet<\/code> and TreeSet<\/code> in the next tutorials.<\/p>\n","protected":false},"excerpt":{"rendered":"In this tutorial, we will learn about the Set interface in Java and its methods. The Set interface of the Java Collections framework provides the features of the mathematical set in Java. It extends the Collection interface. Unlike the List interface, sets cannot contain duplicate elements. Classes that implement Set Since Set is an interface, we cannot create objects from it. In order to use […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[428],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1276"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=1276"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1276\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=1276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=1276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=1276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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