MQL5 ReferenceStandard LibraryGeneric Data CollectionsCHashMap<TKey,TValue>ContainsKey AddCountComparerContainsContainsKeyContainsValueCopyToClearRemoveTryGetValueTrySetValue ContainsKey Determines whether the hash table contains the key/value pair with the specified key. bool ContainsKey( TKey key // key ); Parameters key [in] Key. Return Value Returns true if the hash table contains a key/value pair with the specified key, or false otherwise. Contains ContainsValue