Java ArrayList Example

Java ArrayList class is a resizable array that implements the List interface. It permits all elements, including null and also implements all optional list operations. Most operations that can be run on ArrayList such as size, isEmpty, get, set, iterator and listIterator are all constant time. However, the add operation’s complexity is O(n) time. Compared to LinkedList, the…

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Java LinkedHashSet Example

LinkedHashSet class in Java differs from HashSet as its implementation maintains a doubly-linked list across all elements. This linked list defines the iteration ordering which is the order in which the elements were inserted into the set. It is called an insertion-order. If an element is re-inserted into the set, the insertion order is not affected by…

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Java LinkedHashMap Example

LinkedHashMap is a combination of hash table and linked list that implement the Map interface with predictable iteration order. The difference between HashMap and LinkedHashMap is that LinkedHashMap maintains a doubly-linked list which allows scanning through all of its entries back and forth. The order is maintained, meaning the order in which keys were inserted…

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Java hashCode() Method Example

The super class in Java java.lang.Object provides two important methods for comparing objects: equals() and hashcode(). These methods are widely used when faced against implementing an interaction between classes. In this tutorial, we are only going to look at hashCode(). Method Definition and Implementation hashCode(): By default, this method returns a random integer that is unique every time. If you execute…

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