What is the primary purpose of a `try-catch` block in programming?

The primary purpose of a try-catch block in programming is to handle exceptions and errors gracefully. When writing code, unexpected situations can arise, such as invalid input, file-not-found errors, or network issues. A try-catch block allows developers to write code that can attempt to execute a certain operation in the try section, and if an exception occurs, control is transferred to the catch block. This mechanism enables the program to continue running or to provide informative error messages to users, rather than crashing or behaving unpredictably.

In this way, try-catch blocks play a critical role in enhancing the robustness and reliability of software, as they help developers anticipate and manage potential issues during runtime, ultimately improving the user experience. This stands in contrast to other options such as increasing execution speed, optimizing code structure, or limiting function return values, which are not primary functions of try-catch. The focus of try-catch is specifically on error handling, making it an essential tool in writing resilient and maintainable code.