2 Conditions in if statement

Question

I am trying to detect if the email address is not one of two domains but I am having some trouble with the ruby syntax. I currently have this:

if ( !email_address.end_with?("@domain1.com") or !email_address.end_with?("@domain2.com"))
  #Do Something
end

Is this the right syntax for the conditions?

Looks right, although, you don't need the outer parenthesis. Can you post some more information about your problem? — Jim Deville, Jan 19 '13 at 20:01

score 32 · Accepted Answer · edited Jun 20 '20 at 09:12

32

Rather than an or here, you want a logical && (and) because you are trying to find strings which match neither.

if ( !email_address.end_with?("@domain1.com") && !email_address.end_with?("@domain2.com"))
  #Do Something
end

By using or, if either condition is true, the whole condition will still be false.

Note that I am using && instead of and, since it has a higher precedence. Details are well outlined here

You can build an equivalent condition using unless with the logical or ||

unless email_address.end_with?("@domain1.com") || email_address.end_with?("@domain2.com")

This may be a bit easier to read since both sides of the || don't have to be negated with !.

edited Jun 20 '20 at 09:12

Community

answered Jan 19 '13 at 20:01

Michael Berkowski

2

or, equivalently: unless email_address.end_with?("@domain1.com") || email_address.end_with?("@domain2.com") – Lucas Marcondes Pavelski Jan 19 '13 at 20:07
@LucasMarcondesPavelski added above. I tend to prefer `unless` with logical ands rather than ors but avoiding negation is nice here. – Michael Berkowski Jan 19 '13 at 20:12

score 6 · Answer 2 · answered Jan 19 '13 at 20:45

6

If more domains are added, then the repetitive email_address.end_with? is getting boring real fast. Alternative:

if ["@domain1.com", "@domain2.com"].none?{|domain| email_address.end_with?(domain)}
  #do something
end

answered Jan 19 '13 at 20:45

steenslag

Heh, I was just about to post something like this, except my version was the `unless` ... `any?` form. +1. – Mark Thomas Jan 19 '13 at 20:46
I'll bare this in mind if I need to update it with more domains. – Dean Jan 19 '13 at 21:15

score 5 · Answer 3 · answered Jan 20 '13 at 00:08

5

I forgot end_with? takes multiple arguments:

unless email_address.end_with?("@domain1.com", "@domain2.com")
 #do something
end

answered Jan 20 '13 at 00:08

steenslag

score 3 · Answer 4 · answered Jan 19 '13 at 20:10

3

How about:

(!email_address[/@domain[12]\.com\z/])

answered Jan 19 '13 at 20:10

the Tin Man

4 Answers4