Can a map have 2 values?

Can a map have 2 values?

HashMap can be used to store key-value pairs. But sometimes you may want to store multiple values for the same key. For example: For Key A, you want to store – Apple, Aeroplane.

How do you add multiple values on a map?

21 Answers

1. Use a map that has a list as the value. Map> .
2. Create a new wrapper class and place instances of this wrapper in the map. Map .
3. Use a tuple like class (saves creating lots of wrappers). Map> .
4. Use mulitple maps side-by-side.

What will happen if we put two values with the same key in map?

If you try to insert the duplicate key, it will replace the element of the corresponding key. HashMap is similar to HashTable, but it is unsynchronized. It allows to store the null keys as well, but there should be only one null key object and there can be any number of null values.

Can one key have multiple values?

In python, if we want a dictionary in which one key has multiple values, then we need to associate an object with each key as value. This value object should be capable of having various values inside it. We can either use a tuple or a list as a value in the dictionary to associate multiple values with a key.

Can multiple keys have the same value?

No, each key in a dictionary should be unique. You can’t have two keys with the same value. Attempting to use the same key again will just overwrite the previous value stored. If a key needs to store multiple values, then the value associated with the key should be a list or another dictionary.

Can dictionary have duplicate keys Python?

Python dictionaries don’t support duplicate keys. One way around is to store lists or sets inside the dictionary.

How to map multiple values under the same key?

If you call put (K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values. I use Map for associating multiple values with a key in a Map.

How to associate multiple values with the same key?

A collection similar to a Map, but which may associate multiple values with a single key. If you call put (K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values. I use Map for associating multiple values with a key in a Map.

Can a hashmap have multiple values under the same key?

Take a look at Multimap from the guava-libraries and its implementation – HashMultimap A collection similar to a Map, but which may associate multiple values with a single key. If you call put (K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values.

Is there C # data structure to map keys to multiple values?

Is there a C# data structure to map keys to multiple values? I have a collection of items that I want to key by name; however, the name is not unique. Hashtable and Dictionary only allow unique keys. Lookup seems close to what I want; however, it is not mutable. Is there a built in data structure that I’m missing or do I need to build one myself?