Driver Code
$ str = " GeeksforGeeks " ; if ( uniqueCharacters ( $ str ) ) { echo " The ▁ String ▁ " , $ str , " ▁ has ▁ all ▁ unique ▁ characters STRNEWLINE " ; } else { echo " The ▁ String ▁ " , $ str , " ▁ has ▁ duplicate ▁ characters STRNEWLINE " ; } ? >