Selecting elements from a list

Your list will often be built out of numerous elements and components. Therefore, getting a single element, multiple elements, or a component out of it is not always straightforward. One way to select a component is using the numbered position of that component. For example, to "grab" the first component of my_list you type my_list[[1]]

Another way to check is to refer to the names of the components: my_list[["my_vector"]] selects the my_vector vector.

A last way to grab an element from a list is using the $ sign. The following code would select my_df from my_list: my_list$my_df.

Besides selecting components, you often need to select specific elements out of these components. For example, with my_list[[1]][1] you select from the first component of my_list the first element. This would select the number 1.

Grab the second element of my_list and print it to the console
Grab the first column of the third component of my_list and print it to the console

Take Hint (-30 XP)

Exercise

Selecting elements from a list

Instructions