对 set 的遍历
一般是迭代遍历:
Set<String> set = new HashSet<String>(); Iterator<String> it = set.iterator(); while (it.hasNext()) { String str = it.next(); System.out.println(str); }
for循环遍历:
for (String str : set) { System.out.println(str); }
是不是简单些?
优点还体现在泛型 假如 set中存放的是Object
Set<Object> set = new HashSet<Object>();
for循环遍历:
for (Object obj: set) { if(obj instanceof Integer){ int aa= (Integer)obj; }else if(obj instanceof String){ String aa = (String)obj } ........ }