Programming Concepts Intermediate

What is Hash Table?

A data structure that maps keys to values using a hash function, providing average O(1) time complexity for lookups, insertions, and deletions.

Hash tables compute a hash of the key to determine where to store the value in an array. Collisions (different keys mapping to same index) are handled by chaining (linked lists) or open addressing (probing nearby slots).

Hash tables power dictionaries (Python dict), objects (JavaScript), HashMaps (Java), and associative arrays (PHP). They are the most commonly used data structure for fast key-based lookups. Performance degrades with many collisions or high load factors.

Related Terms

A software development methodology that emphasizes iterative development, collaboration, and rapid response to change.

The process of finding and fixing errors (bugs) in software code to ensure correct program behavior.

A data structure that follows First-In-First-Out (FIFO) ordering, where elements are added at the rear and removed from the front.

DRY (Don't Repeat Yourself)

A software development principle that aims to reduce code duplication by abstracting common patterns into reusable components.

A function that captures and retains access to variables from its enclosing scope, even after that scope has finished executing.

Functional Programming

A programming paradigm that treats computation as the evaluation of mathematical functions, avoiding state changes and mutable data.

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