Ruby range: operators in case statement

Question

I wanted to check if my_number was in a certain range, including the higher Value.

In an IF Statement I\'d simply use \"x > 100 && x <= 500\"

But

Answer 1

It should just work like you said. The below case construct includes the value 500.

case my_number
# between 100 and 500
when 100..500
    puts "Correct, do something"
end

So:

case 500
  when 100..500
    puts "Yep"
end

will return Yep

Or would you like to perform a separate action if the value is exactly 500?

Answer 2

when -Float::INFINITY..0

Would do the trick :)

Answer 3

You could just do:

(1..500).include? x

which is also aliased as member?.

Answer 4

Here's a case way to capture "x > 100 && x <= 500 as desired: a value in a closed range with the start value excluded and the end value included. Also, capturing the ranges before and after that is shown.

case my_number
when ..100;         puts '≤100'
when   100..500;    puts '>100 and ≤500'
when        500..;  puts '>500'
end

Explanations:

• Ranges wit one end left out start from -Infinity resp. go to Infinity. This was introduced in Ruby 2.6.
• Ranges x..y include the end value, ranges x...y exclude the end value.
• All ranges include the start value. To create the equivalent of a range without the start value, you can capture the start value in a preceding when case. That is how the second when case is equivalent to your "x > 100 && x <= 500 even though (100..500).include? 100. Similarly for the third case.