What type of data structure is typically used in a while loop?

In a while loop, the primary focus is on the condition that determines whether the loop should continue executing. The while loop repeatedly executes a block of code as long as a specified condition evaluates to true. This is why the condition is considered a crucial component of the while loop's structure.

The other choices do not represent the central aspect of a while loop. An array, for example, is a collection of elements and does not inherently control the flow of a loop. A function, while it may be called within the loop, is not what drives the loop’s execution. An object may hold data and methods, but it does not play a direct role as the determining factor for the continuation or termination of a while loop.

Thus, the condition is the core element that governs the looping mechanism, making it the correct choice in this context.