**Exception handling** lets the user define the course of action in case an error is raised. When an error arises in the normal execution of the code, the alternative block of code is executed instead.  

Ruby also provides a separate class for exceptions, the **Exception** class, which contains different types of methods. 

# Declaration
Particular keywords help with exception handling. The `begin` and `end` keywords enclose both the main block of code and the rescue block. 

The main block of code is indented after the `raise` keyword, while the code to be executed in case of an error is indented after `rescue`.

# Syntax
```ruby
begin
    raise
      # block where an exception is raised

    rescue
      # block where exception is rescued
end
```
# Multiple rescue clauses
If the exception is not handled by one rescue block, it will be handled by the next run of the rescue code, using the `retry` command. However, extra care is required with the `retry` statement as it may lead to an infinite loop.

# Alternate path
We can use the `else` block to set up an alternate path for execution. If no exception is raised, the else block will run.

# Ensured path
We can use the `ensure` path to hold code that must run, irrespective of whether an exception was raised or not. 



# Code
The following block of code shows how exception handling is done in Ruby: 


# Example code for exception handling


# Exception handling block begins
begin
         
    puts 'Start program...'
         
    # using raise to create an exception  
    raise 'Raising exception here!'
   
    puts 'After exception.' 
   
  # using Rescue method
  rescue    
    puts 'Rescued exception!' 
   
  else # this block runs if no exception raises
  puts "All okay."
  
  ensure # this block always runs 
  puts "Ensure block."
     
# Exception handling block ends 
end    
   
puts 'Outside the exception handling block.'    
   

What is exception handling in Ruby?

Handling exceptions in Ruby allows error management using the `begin`, `rescue`, `else`, and `ensure` blocks.