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 what should I do in a Ruby case (switch)?

Using:

case my_number
when my_number <= 500
    puts "correct"
end

doesn't work.

Note:

The standard Range doesn't include the case if my_number is exactly 500, and I don't want to add the second "when", as I would have to write double Content

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

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

会做的伎俩:)

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.