What does %q do?

Ruby
1

What does %q do in ruby?

2

%q{abc} is equivalent to writing “abc”. It’s most useful when you have
a string literal that contains a lot of characters you’d need to
escape. Compare:

“Gaba L. asked the ruby-talk list, "What does %q do?"”

vs.

%q{Gaba L. asked the ruby-talk list, “What does %q do?”}

And note they’re equal:

a = %q{Gaba L. asked the ruby-talk list, “What does %q do?”}
b = “Gaba L. asked the ruby-talk list, "What does %q do?"”

a == b
=> true

~ jf

John F.
Principal Consultant, BitsBuilder
LI: http://www.linkedin.com/in/johnxf
SO: User John Feminella - Stack Overflow

3

Whoops, small typo:

%q{abc} is equivalent to writing “abc”.

should read:

%q{abc} is equivalent to writing ‘abc’ (single quotes).

By contrast, %Q{abc} is equivalent to writing “abc” (double quotes).
You can see the difference when you try to substitute variables:

f = “apple”

%q{#{f}}
=> “#{f}”
%Q{#{f}}
=> “apple”

~ jf

John F.
Principal Consultant, BitsBuilder
LI: http://www.linkedin.com/in/johnxf
SO: User John Feminella - Stack Overflow

4

Also, lowercase q is like single quotes, but uppercase Q is like double
quotes:

%q(1#{1+1}3) # => “1#{1+1}3”
%Q(1#{1+1}3) # => “123”