Case conversion of a String in R Language – toupper(), tolower(), casefold() and cartr() Function

In this article, we are going to see case conversion of a string in R Programming Language.

R – toupper()

toupper() function in R Language is used to convert the lowercase letters to uppercase.

Syntax: toupper(x) 

Parameters:

x: character vector

Example:

R

# R program to illustrate
# uppercase of vectors

# Create example character string
x <- "GeeksforGeeks"
toupper(x)

print(x)

Output:

GEEKSFORGEEKS

Here in the above code, we have converted an example vector of characters to uppercase characters.

R – tolower() Function

tolower() function is used to convert the uppercase letters to lowercase.

Syntax: tolower(x)

Parameters:

x: character vector

Example:

R

# R program to illustrate
# uppercase of vectors

# Create example character string
x <- "GeeksforGeeks"
tolower(x)

print(x)

Output:

geeksforgeeks

R – casefold() Function

casefold() function takes character vector and boolean value as argument. This boolean value decides the conversion to upper and lower case.

Syntax: casefold(x, upper)

Parameters:

• x: Character Vector
• upper: Boolean value for case conversion

Example 1:

R

# Create example character string
x <- "GeeksforGeeks"

# Convert to lower case letters
x <- casefold(x, upper = FALSE)

print(x)

Output:

"geeksforgeeks"

Here in the above code, the boolean value for the upper is set to be FALSE to convert the character vector to lowercase.

Example 2:

R

# Create example character string
x <- "GeeksforGeeks"

# Convert to upper case letters
casefold(x, upper = TRUE)

print(x)

Output:

"GEEKSFORGEEKS"

Here in the above code, the boolean value for the upper is set to be TRUE to convert the character vector to Uppercase.

R – cartr() Function

cartr() function in R Programming is used when we have to make some characters to upper case and some to lower case.

Syntax: cartr(x, old, new)

Parameters:

• x: character vector
• old: a character string specifying the characters to be translated.
• new: a character string specifying the translations

Example:

R

# Create example character string
x <- "GeeksforGeeks"

# Translate to upper and lower case
chartr(old = "Geeks", new = "GeEkS", x)

Output:

"GeEkSforGeeks"