What is a Hash Table? What is a Key-Value pair?

Difficulty: 2/10

hash table basics, collision handling, key-value storage

Hash Table and Key-Value Pairs

A Hash Table is a data structure that stores data as key-value pairs and uses a hash function to map each key to a location in an underlying array of buckets or slots. The key is used to identify the value. With a well-designed hash function and controlled load factor, lookup, insertion, and deletion are typically O(1) on average.

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Key: uniquely identifies or locates a logical entry.
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Value: data associated with the key.
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The hash function converts the key into a hash code.
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The hash code is mapped to a bucket or slot.
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Average lookup, insertion, and deletion are O(1).
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Collisions must be handled because different keys can map to the same bucket.

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0-2 years experience

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