HashMap myHashMap new HashMap() myHashMap.puta, 'test one') myHashMap.
93 Its a simple question, I have a simple HashMap of which i want to reverse the keys and values. If the map previously contained a mapping for the key, the old value is replaced. The map looks at position 6 and finds nothing, so it answers false. Then you change the key to 6 and use containsKey to ask the map whether it contains the object. public V put (K key, V value) Associates the specified value with the specified key in this map. The HashMap puts your object at the location for hash key 5. If you use the cached value, you use the hash initially computed when the entry was added, and the program ends up actually finding the node you want to remove. Ask Question Asked 9 years, 11 months ago. The replace will be done by put (): From the documentation of HashMap. Because the recomputation of the hash has a different result, it doesn't work. For example if the key is msg id and the values are. You can access items stored in a HashMap using the items key, which is unique for each item. The reason why it's an issue is pretty simple: If you traverse an iterator, removing all entries, the underlying collection should be empty afterwards. I need to create a hashmap with key as integer and it should hold multiple values of different data types. In Java, you use a HashMap to store items in key/value pairs. I provided a TestCase below for the second issue. The second issue, even though developers are not supposed to let an object's hashCode change if it is used in hashing collections, iterator.remove() would fail if the hashCode of the key changed after insertion (given that the bucket for the new value is not the same as for the old hash). 9 Answers Sorted by: 172 Try to remove the element and put it again with the new name. The first issue with this is that it can be faster by using the cached value. Instead, it recomputes it by calling the static hash(Object key) method. The remove method of the instance class HashIterator, within, does not use the Node's cached value for the hash code.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |