Exception Handling in C++

This page might seem like it duplicates some of what we have just seen, but it is valuable because it gives a different perspective on the topic. Read chapter 1 on pages 15-60.

Catching an Exception

The try block

If you're inside a function and you throw an exception (or a called function throws an exception), the function exits because of the thrown exception. If you don't want a throw to leave a function, you can set up a special block within the function where you try to solve your actual programming problem (and potentially generate exceptions). This block is called the try block because you try your various function calls there. The try block is an ordinary scope, preceded by the keyword try:

try {
  // Code that may generate exceptions

If you check for errors by carefully examining the return codes from the functions you use, you need to surround every function call with setup and test code, even if you call the same function several times. With exception handling, you put everything in a try block and handle exceptions after the try block. Thus, your code is a lot easier to write and to read because the goal of the code is not confused with the error handling.