What is the purpose of a loop in programming?

The purpose of a loop in programming is to repeat a block of code as long as a specific condition remains true. This is a fundamental concept in programming, allowing for efficient execution of code that needs to be performed multiple times without having to write the same code repeatedly.

For example, a while loop or a for loop enables you to run a set of instructions an indefinite number of times as long as the defined condition is satisfied. This is particularly useful for tasks such as processing every item in a list, performing calculations until a goal is reached, or continuously prompting a user for input until valid data is provided. By leveraging loops, programmers can create more dynamic and efficient programs that can handle repetitive tasks automatically.

In contrast, executing a block of code only once refers to the basic functionality of sequential code execution. Creating variables of multiple types pertains to data type manipulation, and defining a function relates to code organization and reuse, rather than repetition. Thus, the option that correctly encapsulates the core purpose of a loop is to repeat a block of code based on a condition being true.