Correct way to populate an Array with a Range in Ruby
I am working through a book which gives examples of Ranges being converted to equivalent arrays using their "to_a" methods
When i run the code in irb I get the following warning
warning: default `to_a' will be obsolete
What is the the correct alternative to using to_a?
are there alternate ways to populate an array with a Range?
Solution 1:
You can create an array with a range using splat,
>> a=*(1..10)
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
using Kernel
Array
method,
Array (1..10)
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
or using to_a
(1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Solution 2:
This works for me in irb:
irb> (1..4).to_a
=> [1, 2, 3, 4]
I notice that:
irb> 1..4.to_a
(irb):1: warning: default `to_a' will be obsolete
ArgumentError: bad value for range
from (irb):1
So perhaps you are missing the parentheses?
(I am running Ruby 1.8.6 patchlevel 114)
Solution 3:
Sounds like you're doing this:
0..10.to_a
The warning is from Fixnum#to_a, not from Range#to_a. Try this instead:
(0..10).to_a
Solution 4:
Check this:
a = [*(1..10), :top, *10.downto( 1 )]
Solution 5:
This is another way:
irb> [*1..10]
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]