자바 Set, Map

1.Set
HashSet<Integer> abc = new HashSet<Integer>();
abc.add(1);
abc.add(2);
abc.add(3);

Iterator it = abc.iterator();
Integer temp = 0;
while(it.hasNext()) {
temp = (Integer) it.next();
System.out.println(temp);
}

for(Integer item : abc) {
System.out.println(item);
}

2.Map
HashMap<String,Integer> abc = new HashMap<String,Integer>();
abc.put("a", 0);
abc.put("b", 1);
abc.put("c", 2);

for(String temp:abc.keySet()) {
System.out.println(temp);
}

if(abc.containsKey("a")) {
System.out.println(abc.get("a"));
}

abc.clear();
System.out.println(abc.size());