array0

Array0 is a term used in programming to refer to the zeroth element of an array or, more broadly, to the convention of zero-based indexing in arrays. In most common programming languages today, array elements are addressed by non-negative integers, with the first element located at index 0. The term array0 is not a formal language construct but appears in documentation, tutorials, and code comments to emphasize zero-based access.

Origins and rationale: Zero-based indexing emerged with early languages and systems where pointer arithmetic maps directly to element addressing. In such systems, the element at index i is found at the base address plus i times the element size, making calculations straightforward. This convention can simplify arithmetic in iterations and offset calculations, and it aligns well with array and pointer representations in languages like C and C++.

Implications and variations: While zero-based indexing is widespread, some languages adopt one-based indexing (for example, Fortran traditional arrays, certain mathematical libraries). This difference can lead to off-by-one errors when translating algorithms between languages. In practice, programmers typically use loops that run from 0 to length-1 in zero-based contexts, whereas one-based contexts loop from 1 to length. Documentation often uses the symbol array0 to denote the first element and to distinguish it from other offset conventions, depending on language.

In modern computing, zero-based indexing remains the default in many interfaces and APIs, including core languages such as C, C++, Java, Python, and JavaScript. Some educational resources use array0 as a concrete example to illustrate indexing and iteration patterns, aiding understanding of memory layout, bounds checking, and algorithm correctness across languages.