Keyword

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Keywords. Ruby is object-oriented. Most actions we take are done with methods, part of classes. Iterators (methods) replace loops. The language thus needs fewer keywords.
Ruby Core. Ruby is a scripting language, so its implementation (Ruby Core) is the best source for information on its keywords. This list was built from its code.alias

begin

BEGIN

break

case

class

defined?

do

else

elsif

end

END

ensure

false

for

if

include

module

next

nil

public

protected

private

redo

rescue

retry

self

super

then

true

undef

unless

until

when

while

yield
Some methods. Ruby provides methods that are often used. These are not keywords, but are available in all places in programs. They are useful.p()printputs
Certain keywords, like undef, are rarely used. But learning how they work helps us understand the Ruby language in a more complete way.
In modern Ruby programs, constructs like for-loops are avoided. We find that iterators (like upto and times) are a clearer approach. But these keywords are still provided.