What is a nested array?

A nested array is defined as an array that contains another array. This structure allows for multi-dimensional data representation, which can be very useful in various programming situations. For instance, in a two-dimensional array, each element can itself be an array, representing a matrix or grid-like structure where data points are organized in rows and columns. This capability allows developers to create complex data structures that can model relationships and organize information more efficiently than a simple one-dimensional array.

When working with nested arrays, elements can be accessed using multiple indices, corresponding to their dimensions. For example, in a 2D nested array, you would access elements using two indices, like array[row][column], thus allowing easy manipulation of data stored in a structured format.

The other options describe different characteristics of arrays but do not accurately capture the definition of a nested array. Primitive values refer to simple data types that do not involve multiple structures, fixed size relates to the fact that some arrays cannot dynamically resize after creation, and immutability pertains to arrays that can’t be changed once created. However, these concepts do not overlap with what defines a nested array.