Printing Java Collections Nicely (toString Doesn't Return Pretty Output)
You could convert it to an array and then print that out with Arrays.toString(Object[]):
System.out.println(Arrays.toString(stack.toArray()));
With java 8 streams and collectors it can be done easily:
String format(Collection<?> c) { String s = c.stream().map(Object::toString).collect(Collectors.joining(",")); return String.format("[%s]", s);}first we use map with Object::toString to create Collection<String> and then use joining collector to join every item in collection with , as delimiter.