Beginning R

Adding more items to the list makes the loop go around more times:

my_words <- c("Hello", "R", "Goodbye", "R")

for (word in my_words){
    print(word)
}

Rscript loop.R

[1] "Hello"
[1] "R"
[1] "Goodbye"
[1] "R"

A list with a mixture of data types can be printed witout issue:

my_words <- c("Hello", "R", 404, "Goodbye", "R", 42)

for (word in my_words){
    print(word)
}

Rscript loop.R

[1] "Hello"
[1] "R"
[1] "404"
[1] "Goodbye"
[1] "R"
[1] "42"

Looping over an empty list does not print anything:

my_words <- c()

for (word in my_words){
    print(word)
}

Rscript loop.R