containsValue() 方法的语法为:hashmap.containsValue(Object value) 注:hashmap 是 HashMap 类的一个对象。参数说明:value - 值 返回值如果hashMap 中是否存在指定的 value 对应的映射关系返回 true,否则返回 false。 实例以下实例演示了 containsValue() 方法的使用:...
languages.containsValue("Java")// returns true Here, the specified valueJavais present in the mapping ({2=Java}). Hence, thecontainsValue()method returnstrueand statement insideif blockis executed. Example 2: Add Entry to HashMap if Value is already not present importjava.util.HashMap;class...
(d)containsKey(key)和containsValue(value);返回值为true/false,用于判断hashmap中是否存放有某个数据,两者区别在于根据key值查找还是根据value值查找,根据value值查找的,只要查找到一个就不会继续查找 (e)size(); (f)isEmpty(); (g)equals(Object);判断当前的hashmap对象和目标Object是否相等。这里的比较,会对...
if the specified value is null Remarks Tests if some key maps into the specified value in this table. Note that this method is identical in functionality to#containsValue(Object), and exists solely to ensure full compatibility with classjava.util.Hashtable, which supported this method prior to...
Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key. CompletableFuture<V>getAsync(Transaction txn, K key, Duration timeout, CancellationToken cancellationToken) Returns the value to which the specified key is mapped, or nu...
booleancontainsValue(Objectvalue) Returnstrueif this map maps one or more keys to the specified value. Set<Map.Entry<K,V>>entrySet() Returns aSetview of the mappings contained in this map. Vget(Objectkey) Returns the value to which the specified key is mapped, ornullif this map contains ...
public final boolean contains(Object o) { return containsValue(o); } public final Spliterator<V> spliterator() { return new ValueSpliterator<>(HashMap.this, 0, -1, 0, 0); } public final void forEach(Consumer<? super V> action) { ...
但同时,由于不是对整个Map加锁,导致一些需要扫描整个Map的方法(如size(), containsValue())需要使用特殊的实现,另外一些方法(如clear())甚至放弃了对一致性的要求(ConcurrentHashMap是弱一致性的,具体请查看ConcurrentHashMap能完全替代HashTable吗?)。 ConcurrentHashMap中的分段锁称为Segment,它即类似于HashMap(JDK...
intsize(); // 返回大小booleanisEmpty(); // 是否为空booleancontainsKey(Object key); // 是否包含某个键booleancontainsValue(Object value); // 是否包含某个值V get(Object key); // 获取某个键对应的值 V put(K key, V value); // 存入的数据 V remove(Object key); // 移除某个键voidput...