I would like to use multiple assignment but I don’t care about some part of the values I have in input. So is there a way to assign something to a void variable (aka /dev/null from bash) ? something like nil = 'I wont be used'. I have a more specific example of what I want to achieve below.
My input is :
['no','foo','nop','not at all','bar']
And I assign it this way :
i,foo,dont,care,bar = ['no','foo','nop','not at all','bar']
#or with a splat :
dont,foo,*care,bar = ['no','foo','nop','not at all','bar']
What I would like to do is something like this :
nil,foo,*nil,bar = ['no','foo','nop','not at all','bar']
_, foo, *_, bar = ['no','foo','nop','not at all','bar']
foo #=> "foo"
bar #=> "bar"
_ #=> ["nop", "not at all"]
You could also replace *_ with just *.
Yes, _ is a perfectly valid local variable.
Of course, you don't have to use _ for the values you won't be using. For example, you could write
cat, foo, *dog, bar = ['no','foo','nop','not at all','bar']
Using _ may reduce the chance of errors, but mainly it's for telling the reader that you are not going to use that value. Some prefer using a variable name that begins with an underscore for values that won't be used:
_key, value = [1, 2]
If you assign fewer variables that there are elements of the array, the elements at the end of the array are discarded. For example,
a, b = [1, 2, 3]
a #=> 1
b #=> 2