words <- strsplit("Hello wOrld", "")[[1]];
cat(paste(toupper(words), collapse=""), "") # "HELLO WORLD"
cat(paste(tolower(words), collapse=""), "") # "hello world"
cat(paste(capitalize(words), collapse=""), "") # "Hello WOrld"
cat(paste(decapitalize(words), collapse=""), "") # "hello wOrld"
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