When working with strings in R, it can be handy to know how to quickly change its case. In this tutorial, we will look at how to convert the case of a string to uppercase in R with the help of some examples.
How do I convert a string to uppercase in R?

You can use the built-in toupper()
function to convert a string to uppercase in R. Pass the string you want to convert as an argument to the toupper()
function.
The following is the syntax –
# string s to uppercase toupper(s)
It returns the passed string as an uppercase string.
You can also apply this function to a vector of strings to convert each string in the vector to uppercase.
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Let’s now look at some examples of using the toupper()
function.
Convert string to uppercase
Here, we will create a string with characters having mixed cases. That is some characters will be uppercase and some lowercase. We’ll then pass the string to the toupper()
function.
# create a string s <- "pLeAsE dO nOt tYPe lIkE THiS" # convert string to uppercase print(toupper(s))
Output:
[1] "PLEASE DO NOT TYPE LIKE THIS"
You can see that all the characters in the returned string are in uppercase.
Convert a vector of strings to uppercase
You can also apply the toupper()
function to a vector of strings.
Let’s look at an example.
Here, we will create a vector of some string values and then apply the toupper()
function on the vector itself.
# create a vector of strings vec <- c("HELLO", "Howdy", "hoLA", "namaste") # convert vector to uppercase print(toupper(vec))
Output:
[1] "HELLO" "HOWDY" "HOLA" "NAMASTE"
You can see that each string in the resulting vector is in uppercase.
You might also be interested in –
- R – Remove Whitespaces From String
- Convert Numeric Type to Character Type in R
- Convert Character to Numeric in R (With Examples)
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