Question

How is left_join() different to inner_join()?

A) left_join() retains unmatched rows from the left dataset with NA values in the result, while inner_join() excludes unmatched rows.

B) inner_join() retains unmatched rows from the left dataset with NA values in the result, while left_join() excludes unmatched rows.

C) Both functions behave identically and produce the same result.

D) left_join() and inner_join() are interchangeable terms for the same operation.

Answer 1

left_join() retains all rows from the left data frame with NA for missing matches, while inner_join() only returns rows with matches in both data frames.

Step-by-step explanation:

The difference between left_join() and inner_join() pertains to how they handle rows from the join data that do not match. Answer A is correct: left_join() retains all rows from the left data frame and fills in NA (null values) for missing matches on the right, whereas inner_join() returns only the rows where there are matching values in both data frames. Unmatched rows from either side are excluded in the resulting data frame.