Filtering rows in R Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of filtering rows in R?

Filtering rows means selecting only the rows from a data frame that meet certain conditions. It helps focus on specific data you want to analyze.

beginner

Which function from the dplyr package is commonly used to filter rows?

The filter() function is used to select rows that satisfy given conditions.

beginner

How do you filter rows where the column age is greater than 30 using dplyr?

Use filter(data, age > 30) to keep only rows where the age is more than 30.

intermediate

What happens if you use multiple conditions inside filter() separated by commas?

Multiple conditions separated by commas act like AND. All conditions must be true for a row to be kept.

intermediate

How can you filter rows using base R without dplyr?

Use square brackets with a logical condition, like data[data$age > 30, ] to select rows where age is greater than 30.

Which function is used in dplyr to filter rows?

A arrange()

B select()

C filter()

D mutate()

The filter() function is designed to select rows based on conditions.

What does filter(data, age > 25, gender == 'F') do?

A Selects rows where age > 25 AND gender is 'F'

B Selects rows where age > 25 OR gender is 'F'

C Selects rows where age <= 25 AND gender is not 'F'

D Selects all rows

Multiple conditions separated by commas mean AND, so both must be true.

How do you filter rows in base R where score equals 100?

A data[data$score == 100, ]

B data[score = 100, ]

C filter(data, score == 100)

D data[score == 100]

In base R, use data[data$score == 100, ] to filter rows.

What will filter(data, age > 20, age < 30) return?

A Rows where age is less than 20 or greater than 30

B All rows

C Rows where age is exactly 20 or 30

D Rows where age is between 20 and 30 (exclusive)

Both conditions must be true, so age must be greater than 20 and less than 30.

Which symbol is used for logical AND in dplyr filter conditions?

A &&

B ,

C &

D |

In filter(), multiple conditions separated by commas act as AND.

Explain how to filter rows in R using both dplyr and base R methods.

Think about how you select rows with conditions in both styles.

Describe how multiple conditions work inside the dplyr filter() function.

How do commas affect the filtering?