What is Array in Programming C?

Answer 1

Arrays allow similar types of data to be stored within a contiguous block of memory such that every data element is accessible in constant time, regardless of its physical location within the array. This is achieved through simple pointer arithmetic treating each element as a memory offset from the start of the array. Since every element is the same length (in bytes), locating any element is simply a matter of calculating its offset from its index. Indices are zero-based thus the third element can be found at index 2. The memory offset for that element is therefore the product of the element size and 2. However, C permits indices to be specified directly, while the pointer arithmetic is done in the background. Thus array_name[2] automatically returns a reference to the third element.

Arrays with large and complex variable length data elements need to store those elements separately from the array, usually non-contiguously. This is achieved by using a pointer array. Pointer arrays are particularly useful when sorting extremely large data lists as it is much easier and more efficient to implement a sorting algorithm with an array than it is with a linked list, particularly when constant-time random-access is essential to the algorithm. The time and effort in building the array is generally more than compensated for by the efficiency of the algorithm.

Arrays can also be divided and subdivided to better model the data they represent. For instance, a chessboard might be implemented as a one-dimensional array of 64 elements, however it makes more sense to model the chessboard in a two-dimensional array of 8x8 elements. Although the array is still allocated contiguously and can be thought of as being 8 rows and 8 columns, it's actually better to think of this two-dimensional array as being a one-dimensional array of 8 elements, where each element is another one-dimensional array of 8 elements.

By thinking this way it makes it possible to allocate extremely large arrays in non-contiguous memory (as completely separate one-dimensional arrays) and also makes comprehension of a four-dimensional array in a three-dimensional world that much easier (unless you actually want to model time and space of course).

A four-dimensional array can be thought of in a variety of ways: as being a one dimensional array of three-dimensional arrays, or as a two-dimensional array of two-dimensional arrays, or as a three-dimensional array of one-dimensional arrays, or even as a one-dimensional array of one-dimensional arrays of one-dimensional arrays of one-dimensional arrays. Whichever method you use to imagine your array is immaterial, so long as it makes sense to you that's all that really matters.

Answer 2

An array in C Programming is a homogeneous user defined datatype consisting of multiple data elements occupying contiguous memory locations.

Homogeneous means that the array can only consist of elements of a single data type. Contiguous means that the elements of the array occupy (logically) adjacent memory locations.

Answer 3

An array is a series of one data type.

for example, int numbers[5]; would declare an array of 5 integers.

to access this array, simply use numbers[index] = number or vice versa.

array values start from 0 and go up to the number specified minus one.