Lists

Lists are data constructs that represent a collection of items collected in a defined order. In mathematics and formal logic, a list (often called a sequence) is an ordered collection in which the position of each item is significant and items may repeat. In everyday use, lists appear as bullets or numbers that organize information for quick scanning.

In computer science, a list is a data structure that stores an ordered sequence of elements. Lists can be implemented as linked lists or dynamic arrays, trading constant-time access against insertion costs and memory usage. They support operations such as append, prepend, insert, remove, index-based access, length calculation, and iteration. Many languages provide higher-level helpers such as map, filter, and reduce for processing lists.

Lists can be homogeneous in strictly typed languages, but many modern languages allow lists with mixed types. They can be mutable or immutable depending on the language and implementation. Lists can be nested, forming hierarchical structures that support complex data modeling. In documentation and markup, lists appear as unordered bullets or ordered numbers, and nesting creates multi-level outlines.

Common uses include outlining ideas, maintaining to-do items, storing records, and passing multiple arguments to functions. In markup, lists improve readability and accessibility when properly marked up with semantic list elements. Understanding the properties and operations of lists helps in algorithm design and data organization.