Zarray

Zarray is a term that appears in programming and software-development contexts to denote an array-like or associative data structure. It is not a single standardized library or format; its meaning depends on the ecosystem and implementation being discussed.

In PHP internals, zend_array (often abbreviated zarray) refers to the engine-level representation of PHP arrays. PHP arrays are ordered maps that accept integer and string keys and are implemented as hash-table structures at the C level. The zend_array implementation provides dynamic resizing, key-value storage, iteration order preservation, and the runtime behavior PHP developers expect from arrays. Internal optimizations, such as compact storage layouts and copy-on-write semantics, have evolved across PHP versions to improve memory use and performance.

Outside of PHP, the name "ZArray" or "zarray" is sometimes used by libraries or projects for specialized array abstractions (for example, wrappers that add metadata, bounds checking, or alternate storage strategies). Because usage varies, context is necessary to understand the exact semantics and API.

The term can also be confused with Zarr (with two r’s), a distinct open-source format and Python library for chunked, compressed N-dimensional arrays. When encountering "zarray," verifying the project or language context will clarify which concept is intended.