The Difference between Fail and Raise in Ruby

In this article, you will learn about the difference between fail and raise in Ruby.

The difference between fail and raise in Ruby

In Ruby, “fail” and “raise” are two methods used to handle errors or exceptions in code. Although they are used interchangeably, there is a slight difference between the two.

“fail” is a method that raises an exception with a message. It is considered a lower-level method and is used mainly by Ruby itself rather than by programmers. When “fail” is called, it creates a new exception object with the given message and raises it. For example:

fail "Something went wrong"

“raise” is a more common method used to raise an exception explicitly. It can also be used with or without an argument. If an argument is given, it is used as the error message. If no argument is given, “raise” will re-raise the most recent exception. For example:

raise "Invalid input" if input.nil?
raise ArgumentError, "Invalid argument" if argument.invalid?
raise

In summary, “fail” is a lower-level method used mainly by Ruby itself, while “raise” is a more common method used to explicitly raise an exception. Both methods are used to handle errors or exceptions in code.