Course Content

# R Introduction: Part II

R Introduction: Part II

## Extracting List Elements

Good. Now let's find out how to extract certain elements of a list. The indexing of lists is the same as the indexing of vectors, i.e., the first element has index 1, the second has index 2, and so on. For example, let's extract the second element of the `test` list from the previous chapter.

As you might notice, we extracted the element of list as list itself! It follows that for the example above, you can not perform any arithmetical operations with the extracted element since it is a list, not a number. To output an element from the list with its type, place its index inside double square brackets. For the example above, this will look like this:

If the list has namings, you can use the dollar `\$` sign to access the value with its type straightaway. Also, you can pass the element's name to access its value within both single or double square brackets (like, `test\$text`, `test['text']`, or `test[['text']]`).

Given list `info` from the previous chapter. You need to complete the following tasks:
2. Output class of the element from task 1 using `class()` function.
4. Output class of the element from task 3 using `class()` function.