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);
        }

    }