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Maintenance Ruby 3.3 gets fixes, but no new features. Switch to Ruby 4.0 →

instance method

Resolv::DNS::Name#subdomain_of?

subdomain_of?(other)

Returns true if other is a subdomain.

Example:

Example
domain = Resolv::DNS::Name.create("y.z")
p Resolv::DNS::Name.create("w.x.y.z").subdomain_of?(domain) #=> true
p Resolv::DNS::Name.create("x.y.z").subdomain_of?(domain) #=> true
p Resolv::DNS::Name.create("y.z").subdomain_of?(domain) #=> false
p Resolv::DNS::Name.create("z").subdomain_of?(domain) #=> false
p Resolv::DNS::Name.create("x.y.z.").subdomain_of?(domain) #=> false
p Resolv::DNS::Name.create("w.z").subdomain_of?(domain) #=> false
See also #absolute? #to_s .create also in 3.4 · 3.2 · 3.1 · 3.0