What programming construct is used to perform a specific task or calculation?

A function is a programming construct specifically designed to perform a particular task or calculation. Functions encapsulate a series of statements that can be executed when the function is invoked, allowing for code reuse and modular programming. They can take inputs in the form of parameters and can return outputs, facilitating complex operations and improving readability by breaking down large programs into smaller, manageable pieces.

In contrast, a variable is simply a storage location that holds data, an object is an instance of a class that may contain both data and methods, and an array is a data structure used to store multiple values of the same type. While these constructs are fundamental to programming, they do not inherently perform tasks or calculations like a function does. Functions are essential in structuring code logically and enhancing its maintainability.