What is a common use of the 'for' loop in programming?

The use of a 'for' loop in programming is primarily for iterating over a sequence or collection. This looping construct allows developers to efficiently cycle through elements in structures such as arrays, lists, or any iterable collection. By specifying the starting point, the ending point, and the step increment, a 'for' loop can execute a block of code multiple times, once for each element in the collection.

This capability makes 'for' loops particularly useful for tasks such as processing items in a list, performing calculations on a range of numbers, or applying a function to each element in a dataset. In contrast, other options do not accurately describe the primary function of a 'for' loop. For instance, executing a block of code only once is better suited to other control structures, such as a simple function call or a conditional statement, while variable declaration is not a purpose of the 'for' loop itself, but rather pertains to variable scope and context. Similarly, conditionally executing a block of code relates more closely to 'if' statements or 'while' loops, which are designed for different purposes.