java 基础之list,hashmap遍历取值
http://www.cnblogs.com/wing011203/archive/2013/05/13/3075467.html java基础学习
/* * Collection 属性
* •添加元素:add/addAll
* •清空集合:clear
* •删除元素:remove/removeAll
* •判断集合中是否包含某元素:contains/containsAll
* •判断集合是否为空:isEmpty
* •计算集合中元素的个数:size
* •将集合转换为数组:toArray
* •获取迭代器:iterator */
/** * 迭代list */ private static void setItator() { ArrayList<String> list = new ArrayList<String>(); for (int i = 0; i < 10; i++) { list.add(i + ""); } // 迭代 Iterator<String> iter = list.iterator(); while (iter.hasNext()) { System.out.println("1--->" + iter.next()); } // 遍历 for (String str : list) { System.out.println("2--->" + str); } }
/** * hashmap遍历 */ private static void sethash() { HashMap<String, String> tempMap = new HashMap<String, String>(); for (int i = 0; i < 10; i++) { tempMap.put(i + "", i + ""); } // 用hashmap的ntrySet()来迭代hashmap Iterator<Entry<String, String>> it = tempMap.entrySet().iterator(); while (it.hasNext()) { @SuppressWarnings("rawtypes") Map.Entry entry = (Map.Entry) it.next(); Object key = entry.getKey(); Object value = entry.getValue(); System.out.println("key1=" + key + " value1=" + value); } // 用hashmap的ntrySet()来遍历hashmap for (Entry<String, String> entry : tempMap.entrySet()) { String key = entry.getKey().toString(); String value = entry.getValue().toString(); System.out.println("key2=" + key + " value2=" + value); } }