综合
Associative array
An associative array is an abstract data type storing key–value pairs, also called a map, dictionary, or hash, where each key maps to at most one value.
综合
Java collections framework
The Java collections framework, also known as the Java Collections API, is a unified architecture in Java for representing and manipulating groups of objects, introduced in 1998.
综合
Set (abstract data type)
A set, also known as a set data structure, is an abstract data type that stores unique elements with no duplicates, supporting add, remove, membership, union, intersection, and difference.