Little useless-useful R function

Nothing spectacular, but yet interesting little useless R function for playing with strings and chars.

Converting Sentence case text to mixture of all and small caps resulting in sentence in mixed case.

For example:

"This is useless R Function that seems to exists."

to:

 "This is UsEleSS r FuNcTion THaT SeEms To ExIsTS."

And many other mixture of cases. So by calling this function, the results will give you the mixed cases string.

MixedCases <- function(stavek){
nov_stavek = ""
cifra = 0
crka = ""
is.upper <- "[A-Z]"
is.lower <- "[a-z]"


for (crka in strsplit(stavek, "")[[1]]){
    if (nchar(nov_stavek)<2){
      random_stevilka = sample(0:1, 1, replace=TRUE)
      if (random_stevilka == 0){
        nov_stavek = paste(nov_stavek,toupper(crka), sep = "")
      }
      else {
        nov_stavek = paste(nov_stavek,tolower(crka), sep = "")
      }
    }
   else{
     if(( grepl(pattern = is.upper,  x=(strsplit(nov_stavek,"")[[1]][(cifra-2)])) &  
         grepl(pattern = is.upper,  x=(strsplit(nov_stavek,"")[[1]][(cifra-1)])) |  
         
         grepl(pattern = is.lower,  x=(strsplit(nov_stavek,"")[[1]][(cifra-2)])) &  
         grepl(pattern = is.lower,  x=(strsplit(nov_stavek,"")[[1]][(cifra-1)]))   ) == TRUE){
          if (  grepl(pattern = is.upper,  x=(strsplit(nov_stavek,"")[[1]][(cifra-1)])) ) {
              nov_stavek = paste(nov_stavek, tolower(crka), sep = "")
          }
          else {
           nov_stavek = paste(nov_stavek, toupper(crka), sep = "")
          
            }
     }
    else  {
          random_stevilka = sample(0:1, 1, replace=TRUE)
         if (random_stevilka == 0){
          nov_stavek = paste(nov_stavek, toupper(crka), sep = "") 
          }
        else { 
          nov_stavek = paste(nov_stavek, tolower(crka), sep = "") 
          }
      }
   }
   #cifra = cifra + 1 
  }
  return(nov_stavek)
}

Talk about useless functions

Code is also available at Github. Feel free to improve it with even more wackiness

Happy Rrrring