Vector is a Java class that is found in the java.util package. It is an implementation of a dynamic array, which means that it can grow and shrink as needed while a program is running. This makes it a useful data structure for storing and manipulating large amounts of data, as it allows for efficient insertion, deletion, and access of elements.
One of the main differences between a Vector and an ArrayList is that a Vector is synchronized, which means that it is thread-safe. This makes it a good choice for use in multi-threaded environments, as it ensures that only one thread can access the Vector at a time. However, this synchronization comes at a cost, as it can lead to slower performance compared to an ArrayList.
To create a Vector, we can use the following syntax:
Vector<Type> vectorName = new Vector<Type>();Replace Type with the type of data that we want to store in the Vector, and vectorName with the name we want to give to our Vector. We can also specify the initial capacity and capacity increment of the Vector when we create it. For example:
Vector<String> names = new Vector<String>(10, 5);This creates a Vector that has an initial capacity of 10 elements and increases its capacity by 5 elements each time it needs to expand.
We can add elements to a Vector using the add method:
vectorName.add(element);We can access elements of a Vector using the get method:
Type element = vectorName.get(index);Replace index with the index of the element we want to access. The index of the first element is 0, the index of the second element is 1, and so on.
We can remove elements from a Vector using the remove method:
vectorName.remove(index);We can also remove all elements from a Vector using the clear method:
vectorName.clear();Other useful methods of the Vector class include size, which returns the number of elements in the Vector, and isEmpty, which returns a boolean value indicating whether the Vector is empty.
In summary, the Vector class is a useful data structure for storing and manipulating large amounts of data in Java. It is synchronized, which makes it a good choice for use in multi-threaded environments, but this comes at a cost of potentially slower performance compared to other data structures.