Java Notes-10
发布时间：2020-12-13 20:08:53 所属栏目：PHP教程 来源：网络整理
导读：Summay: The Map Interface,Collection implementations -Maps storeand retrieve elements with key values e.g: MapString,Date dateMap = new HashMapString,Date();dateMap.put( today,new Date() );Date today = dateMap.get( today ); -Functions: pub
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Summay: The Map Interface,Collection implementations -Maps store and retrieve elements with key values e.g: Map<String,Date> dateMap = new HashMap<String,Date>();
dateMap.put( "today",new Date() );
Date today = dateMap.get( "today" ); -Functions: public V put( K key,V value )//This method adds the specified key/value pair to the map.
public V get( K key )//This method retrieves the value corresponding to key from the map.
public V remove( K key )//This method removes the value corresponding to key from the map
public int size()//Use this method to find the number of key/value pairs in this map
public Set keySet()//This method returns a Set that contains all the keys in this map.
public Collection values()//Use this method to retrieve all the values in this map -Map has one child interface, SortedMap . A SortedMap maintains its key/value pairs sorted in a particular order according to the key values. -All of the methods of the Collection interface would appear to make sense for Map, -ConcurrentMap, It extends the base Map interface and adds atomic put,remove,and replace functionality that is public V putIfAbsent( K key,V value )//This method associates the value with the key only if the key was not already in use.
public boolean remove( Object key,Object value )//This method removes the mapping (key and value) only if the current value asso （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |