Repeat and concatenate a string N times

You can use replicate or rep:

replicate(2, "my_string") # [1] "my_string" "my_string" rep("my_string", 2) # [1] "my_string" "my_string" 

paste will put it together:

paste(replicate(2, "my_string"), collapse = "") # [1] "my_stringmy_string" 

With R 3.3.0, we can use strrep from base R

strrep("my_string",2) #[1] "my_stringmy_string" 

We can also pass a vector of values in times

strrep("my_string",1:3) #[1] "my_string" "my_stringmy_string" #[3] "my_stringmy_stringmy_string" 

Use stri_dup function from stringi package

stri_dup("abc",3) [1] "abcabcabc" 

It is also vectorized, so you can do this:

> stri_dup(letters[1:3],4) [1] "aaaa" "bbbb" "cccc" 

Performance comparision :)

> microbenchmark(stri_dup("abc",3),paste(replicate(3, "abc"), collapse = "")) Unit: microseconds expr min lq median uq max neval stri_dup("abc", 3) 2.362 3.456 7.0030 7.853 64.071 100 paste(replicate(3, "abc"), collapse = "") 57.131 61.998 65.2165 68.017 200.626 100 > microbenchmark(stri_dup("abc",300),paste(replicate(300, "abc"), collapse = "")) Unit: microseconds expr min lq median uq max neval stri_dup("abc", 300) 6.441 7.6995 10.2990 13.757 45.784 100 paste(replicate(300, "abc"), collapse = "") 390.137 419.7740 440.5345 460.042 573.975 100 

The stringr library offers the function str_dup():

str_dup("my_string", 2) [1] "my_stringmy_string" 

And it is vectorized over strings and times:

str_dup(c("A", "B", "C"), 2:4) [1] "AA" "BBB" "CCCC"