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#Invent some data
DF <- data.frame(Treat = letters[1:5],
Treat2 = letters[11:15],
Treat3 = 1:5,
Treat4 = letters[21:25]
, stringsAsFactors = FALSE)
DF
#> Treat Treat2 Treat3 Treat4
#> 1 a k 1 u
#> 2 b l 2 v
#> 3 c m 3 w
#> 4 d n 4 x
#> 5 e o 5 y
library(dplyr)
DF2 <- mutate_if(DF, is.character, toupper)
DF2
#> Treat Treat2 Treat3 Treat4
#> 1 A K 1 U
#> 2 B L 2 V
#> 3 C M 3 W
#> 4 D N 4 X
#> 5 E O 5 Y
Created on 2020-01-19 by the reprex package (v0.3.0)