Using object functions

In the previous chapter, you learned about some functions that work with the environment and packages. In this section, we will get to know some basic functions that deal with objects in general. More specifically, I will introduce you to more functions to access the type and dimensions of a data object. You will get an impression of how these concepts can be combined and how they work together.

Testing object types

Although everything in R is an object, objects have different types.

Suppose the object we are dealing with is user-defined. We will create a function that behaves in different ways according to the type of the input object. For example, we need to create a function named take_it that returns the first element if the input object as an atomic vector (for example, numeric vector, character vector, or logical vector), but returns a user-defined element if the input object is a list of data and index.

For example, if the input is a numeric vector such as c(1,...