why this works not right

[Eva]

Hi,

Please take a look at below:

def mytest
return [1..10]
end

x = mytest
x.each do |c| puts c end


this works not as I expected.
I want the output of:
1
2
3
4
5
6
7
8
9
10


But if I change return [1..10] to return 1..10 it will work.
So what's the difference between 1..10 and [1..10]?
THanks.

 

[Steve Klabnik]

[Note: parts of this message were removed to make it a legal post.]

1..10 is a range, while [1..10] is an array with one element, a range from
1..10. You can think of 1..10 as (1..10) and [1..10] as [(1..10)]

I am 95% sure that this is correct, someone please correct me if I'm wrong.
irb seems to support this:

def one_to_ten
1..10
end => nil
one_to_ten.class => Range
[1..10].class

=> Array

 

[Eva]

1..10 is a range, while [1..10] is an array with one element, a range from
1..10. You can think of 1..10 as (1..10) and [1..10] as [(1..10)]

I am 95% sure that this is correct, someone please correct me if I'm wrong.
irb seems to support this:

def one_to_ten
1..10
end => nil
one_to_ten.class => Range
[1..10].class

=> Array

Thanks for the reply. I'm newbie to Ruby,so have another question, I
want to make a function who returns the result which can be used as:

mytest do |a,b|c| do_something end

How to write this mytest?

Regards,
Eva

 

[Justin Collins]

1..10 is a range, while [1..10] is an array with one element, a range from
1..10. You can think of 1..10 as (1..10) and [1..10] as [(1..10)]

I am 95% sure that this is correct, someone please correct me if I'm wrong.
irb seems to support this:

def one_to_ten

1..10
end

=> nil

one_to_ten.class

=> Range

[1..10].class

=> Array

Thanks for the reply. I'm newbie to Ruby,so have another question, I
want to make a function who returns the result which can be used as:

mytest do |a,b|c| do_something end

How to write this mytest?

Regards,
Eva

The do...end is actually creating a block, which is passed into your
method. There are two ways of having functions accept blocks:

#Explicitly
def mytest &block
block.call 1, 2, 3
end

#Implicitly
def mytest
yield 1, 2, 3
end

Either way can be called like

mytest do |a,b,c|
do_something_with a, b, c
end

You will probably want to read up on methods and blocks and how the two
can be used together.

-Justin

 

[Eva]

Thanks all!
Merry Christmas Ruby world.

 

[Marnen Laibow-Koser]

Hi,

Please take a look at below:

def mytest
return [1..10]
end

x = mytest
x.each do |c| puts c end


this works not as I expected.
I want the output of:
1
2
3
4
5
6
7
8
9
10


But if I change return [1..10] to return 1..10 it will work.
So what's the difference between 1..10 and [1..10]?

1..10 is a Range. [1..10] is an Array with one element (that happens to
be a Range, but that's irrelevant). Range#each returns each element in
the range, so you get 1, 2, 3, etc. Array#each likewise returns each
element in the array -- but your array only has one element, the Range
object itself!

If you want an Array with the elements 1 to 10, you need something like
(1..10).to_a .

THanks.

Best,