Excellent! You now know how to create a vector, name its values, and extract elements from it. The next step we will explore is how to modify a vector by adding new items to it or deleting existing ones.

There are a couple of methods to add a new value to an existing vector. Suppose we have a vector named vec and we wish to append new_value to it, with the name 'new_name' assigned to this new value. The diagram below illustrates both methods.

For instance, let’s apply these methods using the grades example by adding a new grade, 60, for the subject 'Philosophy'. The first method involves utilizing vectors:

Now, let’s try the second method where we assign a name to the value as we add it.

Thus, if your vector does not have names, the first method is more appropriate. However, if your vector already has names, the second method is preferable. With the second method, you can add new values and also reassign them. For example, if you execute grades['Math'] <- 100, the original grade of 80 for Math will be updated to 100. You can achieve the same result by referring to the index, like this: grades[1] <- 100.