elementsize

Elementsize is a term used to describe the amount of memory or storage consumed by a single element in a collection, data structure, or encoded unit. In programming and computer science, it is typically expressed in bytes and depends on the data type and the memory model of the language or platform. For fixed-size elements such as primitive types, the element size is constant (for example, sizeof(int) in C). For arrays, the total size is often calculated as elementsize multiplied by the number of elements; however, this assumes a uniform element size and may be complicated by padding or alignment rules in structs.

In languages with references or objects, the logical element size may differ from the actual memory footprint because the element may be a reference to a heap-allocated object. In image and multimedia data, elementsize is used to denote bytes per pixel (for example, 3 bytes per pixel for RGB, 4 for RGBA).

Considerations for computing elementsize include alignment, padding, and platform differences that influence memory layout. When parsing or serializing data, elementsize is important for calculating offsets and buffer sizes and for avoiding overflow.

Examples help illustrate the concept: in C, an array such as int a[10] has elementsize equal to sizeof(int); if that is 4, the total size of the array’s element storage is 40 bytes. In image processing, a pixel with RGBA color uses 4 bytes per pixel, so elementsize is 4 in that context.

See also: size_t, sizeof, memory layout, serialization, alignment.