question: public static String replaceChars ( String s , char [ ] sub , char [ ] with ) { char [ ] str = s . toCharArray ( ) ; for ( int i = 0 ; i < str . length ; i ++ ) { char c = str [ i ] ; for ( int j = 0 ; j < sub . length ; j ++ ) { if ( c == sub [ j ] ) { str [ i ] = with [ j ] ; break ; } } } return new String ( str ) ; }
target:  Replaces all occurrences of a characters in a string.