This chapter explores key Java collections: arrays for ordered data, sets for unique, unordered elements, and maps for key-value pairs, helping you manage and organize data efficiently.
A Hashtable in Java is a data structure that stores data in key-value pairs. It’s like a dictionary you use a key to find a value. Example: hashtable.put(“name”, “John”); Now you can get the value “John” by using the key “name”. Now, Why No Null Keys or Values? Java’s Hashtable does not allow null as … Read more
A HashMap is a part of the Java Collections Framework and is used to store data in key-value pairs. It allows one null key and multiple null values, and it is not synchronized, making it faster but not thread-safe. A Hashtable is a legacy class in Java that also stores data in key-value pairs. It … Read more
An ArrayList in Java is a resizable array that can store a collection of elements. It allows you to add, remove, and access elements, and automatically adjusts its size as needed when elements are added or removed. Unlike regular arrays, you don’t need to specify the size in advance. It is a class in Java … Read more