Question

Explain briefly the operation of each of the following methods of class Vector: a) add b) insertElementat c) set d) remove e) removeAT 7 Elements f) removeElementat g) firstElement h) lastElement i) isEmpty j) contains k) indexof I) size \(\mathrm{m})\) capacity

Short answer

The methods manipulate and interact with elements in a Vector, such as adding, removing, checking size, and retrieving elements.

Step-by-step solution

Method 'add'

The 'add' method is used to add an element to the end of the Vector. It increases the size of the Vector by one and appends the specified element to the end.

Method 'insertElementAt'

The 'insertElementAt' method inserts the specified element at the specified index in the Vector. It shifts the element currently at that position (if any) and any subsequent elements to the right, increasing their indices by one.

Method 'set'

The 'set' method replaces the element at the specified position in the Vector with the specified element. It is used to update the element at a particular index.

Method 'remove'

The 'remove' method removes the first occurrence of the specified element from the Vector, if it is present. This method typically decreases the size of the Vector by one.

Method 'removeElementAt'

The 'removeElementAt' method removes the element at a specified index from the Vector. It shifts any subsequent elements to the left, subtracting one from their indices.

Method 'firstElement'

The 'firstElement' method returns the first element in the Vector. This method does not remove the element but only retrieves it.

Method 'lastElement'

The 'lastElement' method retrieves the last element in the Vector. Similar to 'firstElement', it does not remove the element from the Vector.

Method 'isEmpty'

The 'isEmpty' method checks whether the Vector contains no elements. It returns true if the Vector is empty and false otherwise.

Method 'contains'

The 'contains' method checks if the Vector contains a specified element. It returns true if the element is found and false otherwise.

Method 'indexOf'

The 'indexOf' method returns the index of the first occurrence of the specified element in the Vector, or -1 if the Vector does not contain the element.

Method 'size'

The 'size' method returns the number of elements currently stored in the Vector. It provides the current count of elements without including capacity details.

Method 'capacity'

The 'capacity' method returns the current capacity of the Vector, indicating how many elements the Vector can hold without needing to resize or expand.

Step Correction

There is no method named 'removeAT 7 Elements' in the standard Vector class. This could be an error or a misunderstanding of existing methods.

Key concepts

add method

The 'add' method is a fundamental operation in the class Vector, designed to append elements seamlessly to the data structure. When you use the 'add' method, it places the new element at the very end of the Vector. This automatic positioning helps manage the order efficiently, allowing each addition to naturally follow the previous elements.

One of the key functions of the 'add' method is that it automatically increases the Vector's size by one each time an element is added. This is important because it means you don't need to pre-define the exact size of the Vector before usage, offering flexibility in how you manage collections of data. This automatic resizing ensures that there's always room for more data, provided the underlying system can accommodate it.

removeElementAt method

The 'removeElementAt' method is integral for managing and modifying the contents of a Vector by making structural changes. This method allows you to specifically target and remove an element at a given index. When the 'removeElementAt' method is invoked, the element located at the specified index will be deleted.

Importantly, once an element is removed, the Vector automatically adjusts itself by shifting all elements that follow the removed element one position to the left. This shift closes the gap created by the removed element, ensuring the continuity and stable order of the remaining elements. It should be noted, however, that because of this repositioning, the indices of the affected elements will also change. These auto-adjustments are crucial for maintaining a tidy and efficient data structure.

isEmpty method

Sometimes you just need a simple check to know if there's anything stored in a structure like a Vector. This is where the 'isEmpty' method comes into play. The 'isEmpty' method is used to quickly determine whether a Vector contains any elements or if it's currently empty.

When called, the 'isEmpty' method evaluates the state of the Vector and returns a boolean value:

• It returns 'true' if there are no elements present in the Vector, indicating emptiness.
• It returns 'false' if there is at least one element in the Vector, indicating that it contains data.

This straightforward functionality can be very useful in conditions where proceeding further relies on the presence of data.

capacity method

In the context of a Vector, its 'capacity' signifies its potential to hold elements before necessitating a resize. The 'capacity' method provides insight into this storage potential by returning the current capacity of the Vector.

Understanding the capacity is crucial because, while the 'size' of a Vector tells you how many elements are actually stored, the 'capacity' tells you how many it can hold before requiring more memory allocation. This is beneficial for optimization and memory management, as you can be proactive about when your data structure might need to grow. It’s a preemptive signal to anticipate and handle future storage needs efficiently.