Wiktionary
n. (context computing programming English) A data structure, especially one that serves to group a number of fields (in contrast to an object-oriented class with methods) or one that is passed by value rather than by reference.
Wikipedia
A struct in the C programming language (and many derivatives) is a complex data type declaration that defines a physically grouped list of variables to be placed under one name in a block of memory, allowing the different variables to be accessed via a single pointer, or the struct declared name which returns the same address. The struct can contain many other complex and simple data types in an association, so is a natural organizing type for records like the mixed data types in lists of directory entries reading a hard drive (file length, name, extension, physical (cylinder, disk, head indexes) address, etc.), or other mixed record type (patient names, address, telephone... insurance codes, balance, etc.).
The C struct directly corresponds to the assembly language data type of the same use, and both reference a contiguous block of physical memory, usually delimited (sized) by word-length boundaries. Language implementations which could utilize half-word or byte boundaries (giving denser packing, using less memory) were considered advanced in the mid-eighties. Being a block of contiguous memory, each variable within is located at a fixed offset from the index zero reference, the pointer. As an illustration, many BASIC interpreters once fielded a string data struct organization with one value recording string length, one indexing (cursor value of) the previous line, one pointing to the string data.
Because the contents of a struct are stored in contiguous memory, the sizeof operator must be used to get the number of bytes needed to store a particular type of struct, just as it can be used for primitives. The alignment of particular fields in the struct (with respect to word boundaries) is implementation-specific and may include padding, although modern compilers typically support the #pragma pack directive, which changes the size in bytes used for alignment.
In the C++ language, a struct is identical to a C++ class but a difference in the default visibility exists: class members are by default private, whereas struct members are by default public.
Usage examples of "struct".
He sat to my left and whispered very softly in my ear that perhaps the two old men had in- structed me but I did not remember, or that they had not said anything about it so I would not fix my attention on it once I had found it.
A lookout tower was being con structed on the east side of the sentry hut.
He could see the somber black dome of Al Aqsa, started by Abdul Malik ibn Marwan, completed by his son Al-Walid in the year 705, recon structed in the year 1035, then refurbished during the Second World War.
Instead of learning from her century, she seems determined to turn her back on it, to the extent of an eremitical existence somewhere, apparently, in California, judging from the recurrence of redwood trees, Hispanic farm workers, and unrecon structed flower children gone somewhat to seed.
Many of the abandoned cities and mining and manufacturing complexes in the north and south temperate regions were many centuries old, and so well con- structed that only a moderate effort would be required to restore them because the mineral wealth of the planet was far from exhausted.
They were normal in most respects: flexible mylar and plexulose con structs with polarizing faceplates, air tanks, powerpacks, helmet radios, belt-clips for tools or guns.