This method can be used to retrieve a specific exception message from a raised exception object.
Ruby rescue exception type.
The code above will rescue every exception.
That s because ruby uses exceptions for things other than errors.
Ruby does require some form of begin to appear before the rescue.
Or i will stab you.
You ve learned about errors in ruby basic exception handling the rescue begin keywords.
The code in an else clause is executed if the code in the body of the begin statement runs to completion without.
At its core every ruby exception stems from a built in exception class and includes a handful of built in methods but the most commonly used exception method is message.
Ruby s exception hierarchy is used to differentiate between different types of errors while giving you the ability to rescue from a group of errors without specifying all of them.
It places the keyword rescue after any code that would probably throw an exception.
While it may be tempting to rescue every child of the exception class it is generally considered bad practice due to the way the ruby exception hierarchy is structured.
The match will succeed if the exception named in the rescue clause is the same as the type of the currently thrown exception or is a superclass of that exception.
Ryan davis s ruby quickref says without explanation.
It will be unkillable except by kill 9.
Become a better developer.
For each rescue clause in the begin block ruby compares the raised exception against each of the parameters in turn.
For each rescue clause in the begin block ruby compares the raised exception against each of the parameters in turn.
The match will succeed if the exception named in the rescue clause is the same as the type of the currently thrown exception or is a superclass of that exception.
Rescuing signalexception prevents the program from responding correctly to signals.
It also uses them to handle messages from the operating system called signals if you ve ever pressed ctrl c to exit a program you ve used a signal.
What s the right thing to do.
It ll break your program in weird ways.
The general syntax for the rescue statement is as follows.
Ruby s exception handling mechanism is simple.
Rescuing interrupt prevents the user from using ctrlc to exit the program.
Exception is the root of ruby s exception hierarchy so when you rescue exception you rescue from everything including subclasses such as syntaxerror loaderror and interrupt.
How to handle an exception.
