Solved: try/catch

Try and catch blocks are fundamental components of error handling in most modern programming languages, including MATLAB. Their use is crucial in preventing critical failures and improve user experience as they allow the developer to take necessary actions when an error occurs.

The try/catch mechanism works by setting specific parts of the code to be monitored for errors (‘try’) and actions to perform if an error is detected (‘catch’).

Now, let’s dive into the main topic with a solution for a common problem.

Unexpected Input in a MATLAB Function

A common problem in MATLAB is handling unexpected input in a function. Without proper error handling, it becomes an issue because it can cause the function to fail entirely and crash the program. This is exactly where a try/catch can be a savior.

function res = handledFunction(input)
  try
    % Potentially problematic code
    res = sqrt(input);
  catch ME
    % Handle the exception
    disp('An error occurred while calculating the square root.')
    disp(getReport(ME, 'basic'))
  end
end

Step by Step Explanation of the Code

The function `handledFunction` is designed to compute the square root of its input. However, if we have an input that doesn’t allow the computation of a square root (like a negative number), MATLAB would usually throw an error and halt.

• First, we put the code that can potentially throw an error inside a try block. If the code executes successfully, the catch block is skipped.
• If an error does occur inside the try block, the program control is passed to the catch block, skipping any other code in the try block. The catch block is designed to handle error gracefully, instead of halting the entire program execution. The error information can be accessed through the specified variable, in this case, `ME`.
• Finally, `getReport(ME, ‘basic’)` provides a brief report about the error that occurred. This could be crucial for debugging or for displaying a meaningful error message to the end user.

Situations, Libraries and Functions Similar

The try/catch structure is not limited to functions. It can be used anywhere in the code where an error might occur. Meaningful error handling can improve the robustness of the program, providing alternate solutions, or correctly releasing resources after an error has occurred.

Another similar MATLAB function that can be used for error handling is `error`. It allows you to create custom error messages and works well with try/catch blocks.

Furthermore, the MException class in MATLAB provides more advanced features for capturing and handling errors. You can create MException objects, throw them, and catch them within a try/catch block.

Error handling is a crucial part of programming, and all coders should be familiar with the concepts and tools available in their preferred language to handle errors effectively. Whether through the use of try/catch in MATLAB or similar constructs in other languages, ensuring that your program can handle unexpected input or errors is a key part of crafting robust, resilient code.