Question

What is the function used to test objects (returns a logical operator) if they are NA?

(a) is.na()

(b) is.nan()

(c) as.na()

(d) as.nan()

I had been asked this question during an online exam.

The above asked question is from Overview of R topic in chapter History, Overview and Getting Started of R Programming

Answer 1

The correct option is (a) is.na()

The explanation: is.na() is the function used to test if they are NA. We can check NA ‘s at any stage of the code. Generally, We will remove the NA’s for the operations in R like mean etc.., is.na() is used to test objects if they are NA.