  Course Content

# R Introduction: Part I

R Introduction: Part I

##   Modifying

Great! So far, you know how to create a vector, assign names to values, and extract elements from it. The next thing we will consider is modifying: adding and deleting existing items from a vector.

There are at least two ways to add a new value to an existing vector. Assume we have a vector named `vec` and want to add `new_value` to it. The name we want to assign to this value is `'new_name'`. Both ways are displayed on the schema below. For example, let me show you how both ways will work. Let's use the same grades example and add a new grade `60` for the `'Philosophy'` subject. The first way is using vectors:  Now let's perform the second method - assigning names with values simultaneously.  So, if your vector has no names, then the first method is better. But if the vector has names - then it's better to use the second method. Using the second method, you can add new values and reassign them. For example, if you write `grades['Math'] <- 100` - then the original value of `80` will be rewritten with `100`. Also, you can refer to a specific index. The same trick can be done by writing `grades <- 100`.

1. Add a new item named `'Desk'` with the value of price `135` to the end of the `prices` vector using the second method (assigning name simultaneously to adding value).
2. Change price of item `'Bookshelf'` to `180`. Feel free to use either index or name.
3. Output modified vector `prices`. 