hashmap

What is a HashMap?

• A data structure for storing ordered key-value pairs

• A data structure for storing unordered key-value pairs that uses a hash function for fast access.

• A data structure that uses trees to store values

• A data structure for storing homogeneous elements.

How can you create an empty HashMap?

• hash_map = {}

• hash_map = []

• hash_map = set()

• hash_map = dict()

How do you insert a key-value pair into a HashMap?

• hash_map.add("apple", 5)

• hash_map.put("apple", 5)

• hash_map["apple"] = 5

• hash_map.insert("apple", 5)

How do you check if a key exists in a HashMap?

• key.exists("apple")

• hash_map.contains("apple")

• hash_map.has_key("apple")

• "apple" in hash_map

What happens if you try to retrieve a value for a non-existing key in a HashMap?

• A KeyError will be raised

• It returns None

• It returns a default value if specified

• It returns an empty value (e.g., "" or 0).

How do you remove a key-value pair from a HashMap?

• hash_map.remove("apple")

• hash_map.del("apple")

• - del hash_map["apple"]

• hash_map.delete("apple")

How do you update the value for an existing key in a HashMap?

• hash_map["apple"] = new_value

• hash_map.update("apple", new_value)

• hash_map.set("apple", new_value)

• hash_map.insert("apple", new_value)

How do you get all the keys in a HashMap?

• hash_map.all_keys()

• hash_map.keys()

• hash_map.get_keys()

• hash_map.get_all_keys()

How does Python handle collisions in a HashMap (dictionary)?

• Python does not handle collisions, they result in an error.

• Python resolves collisions using methods like open addressing or chaining.

• Python always stores two keys at the same location if they collide

• Python simply ignores collisions and stores only the last added key

How do you get all elements in a HashMap as pairs (key, value)?

• hash_map.pairs()

• hash_map.get_items()

• hash_map.items()

• hash_map.all()