I am a newbie about Ruby on Rails. I know << operator what it is doing but I am working with datatable and I have codes like these:
def data
items.map do |donation|
[].tap do |column|
column << donation_path(donation)
column <<= current_user.admin? ? link_to(donation.sender.name, admin_store_path(donation.sender)) : donation.sender.name
end
end
end
I tried to <<= in rails c and the result is:
irb(main):001:0> ar = []
=> []
irb(main):002:0> ar << 1
=> [1]
irb(main):003:0> ar <<= 1
=> [1, 1]
irb(main):004:0> ar <<= 2
=> [1, 1, 2]
I think <<= is similar with << but I have to be sure.
If you use an operator op= in Ruby, the expression
x op= y
is equivalent to
x = x op y
In your case, it means that an
a <<= b
is equivalent to
a = a << b
but since a << b already modifies a, you gain nothing from using <<=.
NOTE: As was pointed out in the comments, this does not apply for the operator []: If you want to have an assignment version, you have to define []= explicitly.