IntermediateTopic 39 of 104Software & Computing
Exceptions and error handling
Handle failures predictably without crashing.
In depth
Exceptions signal abnormal conditions and separate error handling from normal flow with try/catch/finally. Best practice: catch specific exceptions, fail fast, clean up resources (with, RAII, finally), log context, don't swallow errors. Alternatives: error codes and Result types.
Key points
- Checked vs unchecked
- Custom exceptions
- Retry and fallback
ExampleOpening a missing file raises FileNotFoundError, which the program can handle.
What is Exceptions and error handling?
Handle failures predictably without crashing.
Why is it important to understand exceptions and error handling?
Exceptions let programs handle errors without crashing and keep the error logic separate from normal flow, which is important for reliability.
When should I use exceptions?
For unexpected failures that the caller may need to handle, rather than for normal control flow such as an ordinary search failing to find an item.
What is a good practice when catching an exception?
Catch only the errors you can handle, avoid silently ignoring them, and include context when you log or rethrow.
How is Exceptions and error handling used in practice?
Typical applications include catching a file-not-found error and showing a clear message to the user, retrying a network request after a temporary failure and logging an invalid sensor reading and continuing the program.
What should I learn before Exceptions and error handling?
Study "Functional programming" first (topic 38 of 104 in Software & Computing). It covers the groundwork this topic builds on.
What are the key points of Exceptions and error handling?
Checked vs unchecked. Custom exceptions. Retry and fallback.
Can you give an example of Exceptions and error handling?
Opening a missing file raises FileNotFoundError, which the program can handle.
What comes after Exceptions and error handling?
The next topic is "Memory management", which builds directly on this one.
How difficult is Exceptions and error handling?
It is classed as Intermediate in Software & Computing (topic 39 of 104). It is an intermediate topic. Work through the beginner topics in Software & Computing first.