public static String join(List<?> things,String delim){
  StringBuilder builder=new StringBuilder();
  boolean first=true;
  for (  Object thing : things) {
    if (first) {
      first=false;
    }
 else {
      builder.append(delim);
    }
    builder.append(thing.toString());
  }
  return builder.toString();
}

public static String join ( List < ? > things , String delim ) { StringBuilder builder = new StringBuilder ( ) ; boolean first = true ; for ( Object thing : things ) { if ( first ) { first = false ; } else { builder . append ( delim ) ; } builder . append ( thing . toString ( ) ) ; } return builder . toString ( ) ; }
returns a list joined together by the provided delimiter , for example , [ " a " , " b " , " c " ] could be joined into " a , b , c "
