Using a Shorter Syntax for Exception Handling
Remember how we got input from the user to fill in an array and handled a possible exception with begin/rescue in Getting Input? You can write that kind of code much more succinctly. First, let’s rewrite that code with a few methods to give it more structure:
| | puts "Enter the numbers one by one, and end with an empty line:" |
| | input_array # => for example: [78, 56, 12] |
| | |
| | def input_array |
| | arr = [] of Int8 |
| | while number = gets |
| | number = number.strip # removes leading or trailing whitespace |
| | if number == "" || number == "stop" |
| | break |
| | end |
| | add_to_array(arr, number) |
| | end |
| | arr |
| | end |
| | |
| | def add_to_array(arr, number) |
| | begin |
| | arr << number.to_i8 |
| | rescue |
| | puts "integer bigger than 255" |
| | end |
| | end |
The method add_to_array now handles the possible exception. You can write this more concisely by leaving out the begin keyword, as shown here:
| | def add_to_array(arr, number) |
| | arr << number.to_i8 |
| | rescue |
| | puts "integer bigger than 255" |
| | end |
This shorthand also works for ensure, which is usually used for freeing resources or cleaning up.
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