A hash table is a data structure that allows for efficient data retrieval and storage by associating keys with values. It uses a hash function to compute an index into an array of buckets or slots, from which the desired value can be found. The hash function takes the input key and produces a hash code, which is used to determine the index where the corresponding value should be stored or looked up.
The key advantage of hash tables is their ability to provide fast access to values based on keys. This makes them well-suited for applications where efficient data retrieval is crucial, such as in databases, caches, or symbol tables in programming languages.
However, the efficiency depends on the quality of the hash function and the handling of collisions. A good hash function minimizes collisions, and effective collision resolution strategies maintain the performance of the hash table.
key components of hash table includes
Hash Function: The hash function takes a key as input and produces a hash code, which is typically an integer. This code is used as an index to access the corresponding slot in the array. Designing a good hash function is crucial for the efficiency and effectiveness of a hash table. A good hash function minimizes collisions, distributes keys uniformly across the hash table, and provides a relatively random distribution of hash codes
Array of Buckets: The hash table maintains an array (often called a bucket array or simply an array) where each element is a slot or bucket. Each bucket can store one or more key-value pairs.
Indexing: The hash code is used to determine the index in the array where the key-value pair should be stored or looked up.
Collision Handling: Collisions can occur when two different keys produce the same hash code. Hash tables employ techniques to handle collisions, such as chaining (each bucket contains a linked list of key-value pairs) or open addressing (finding the next available slot in the array).
Efficient Retrieval: When you want to retrieve a value associated with a key, the hash function computes the hash code, and the corresponding array index is used to quickly locate the value.
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