Character (string) type in R Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a character type in R?

A character type in R is used to store text or strings, like words or sentences, inside quotes.

beginner

How do you create a character string in R?

You create a character string by putting text inside single or double quotes, for example: "hello" or 'world'.

beginner

What function checks if a value is a character in R?

The function is.character() returns TRUE if the value is a character string, otherwise FALSE.

beginner

How does R treat a single letter inside quotes?

R treats a single letter inside quotes as a character string of length one, not as a separate type.

intermediate

What happens if you mix numbers and characters in a vector in R?

R converts all elements to character type because a vector must have elements of the same type.

How do you create a character string in R?

A Put text inside quotes, like "hello"

B Write text without quotes

C Use the number format

D Use the TRUE or FALSE keywords

In R, character strings must be inside single or double quotes.

What does is.character("R") return?

A An error

B FALSE

C TRUE

D NULL

The value "R" is a character string, so is.character returns TRUE.

What type does R assign to c("a", 1, TRUE)?

A Logical

B Numeric

C List

D Character

R converts all elements to character because vectors must have one type.

Which function checks if a variable is a character string?

A is.character()

B is.numeric()

C is.logical()

D is.vector()

is.character() returns TRUE if the input is a character string.

What is the length of the character string "a" in R?

A 0

B 1

C 2

D Depends on the font

A single character string has length 1 in R.

Explain how R handles character strings and how to create them.

Think about how you write words in R code.

Describe what happens when you mix characters and numbers in a vector in R.

Remember vectors need one type only.