Error Handling

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Error Handling[edit]

Error Handling

Error Handling in Elixir is an essential aspect of programming, allowing developers to gracefully handle and recover from exceptions and errors that may occur during the execution of a program. Elixir provides a powerful and flexible error handling mechanism that promotes the building of robust and fault-tolerant applications.

Types of Errors[edit]

Elixir classifies errors into two main types: **errors** and **exceptions**. Understanding the distinction between the two is crucial for effective error handling.

  • **Errors** are situations that prevent normal program execution and usually indicate severe issues in the system. They can be caused by factors such as missing resources or system failures.
  • **Exceptions** are exceptional conditions that can occur during program execution but are generally recoverable. Examples include arithmetic division by zero or attempting to access a non-existent key in a map.

Error Handling Techniques[edit]

Elixir offers several techniques for handling errors and exceptions:


The `try/rescue` construct is a fundamental error handling mechanism in Elixir. It allows you to attempt a block of code and rescue any raised exceptions.

```elixir try do

 # Code that may raise an exception


 exception_type -> # Handle the exception

end ```


The `raise` function allows you to explicitly raise exceptions. It is useful for signaling exceptional conditions and triggering specific error handling logic.

```elixir raise ExceptionType, message, stacktrace ```

Exception Safe[edit]

Elixir provides **exception-safe** constructs that ensure your code is executed even in the presence of exceptions. These constructs include `with`, `catch` and `after`.


Elixir offers monitoring mechanisms to supervise processes and detect failures. These mechanisms include `GenServer`, `Supervisor`, and `Registry`, which can be utilized to monitor and recover from errors.

Best Practices[edit]

To ensure robust and maintainable code, it is recommended to follow the following best practices when handling errors in Elixir:

  • **Fail Fast**: Detect and handle errors as soon as possible to prevent further issues.
  • **Use Typespecs**: Leverage Elixir's typespecs to document and enforce error handling contracts.
  • **Log Errors**: Logging errors can help in debugging and understanding system behavior.
  • **Handle Exceptions Locally**: Handle exceptions at the appropriate level, keeping exception-handling logic close to where it occurs.


Proper error handling is crucial for building reliable and resilient software systems. Elixir provides a comprehensive set of error handling techniques and mechanisms to tackle errors and exceptions effectively. By understanding and utilizing these tools, developers can create fault-tolerant applications that gracefully recover from unexpected situations.

For more information on error handling in Elixir, check out the article on Error Handling Patterns.