a deepcopy for "array = [1,2,3]*5"?

[Boris]

Been looking this up in the myriad of deepcopy strands, but couldn't
find it in 30 minutes, so I'm posting the question.

The question is simple. What way would you create an array that
contains 5 copies of an array, without the copies interfering with each
other?

array = [1,2,3]*5

generates:
[[1,2,3],[1,2,3],[1,2,3],[1,2,3],[1,2,3]]

but unfortunately also makes 'array[1][1] = "a"' change it like this:

[[1,"a",3],[1,"a",3],[1,"a",3],[1,"a",3],[1,"a",3]]

---------
Anyway, found a solution during tinkering, although I don't know why.
Thought I'd just still post it anyway.

ar = []
5.times{ar << [1,2,3]}

works, and 'array[1][1] = "a"' results in the thing I want

[[1,2,3],[1,"a",3],[1,2,3],[1,2,3],[1,2,3]]

 

[Florian Frank]

The question is simple. What way would you create an array that
contains 5 copies of an array, without the copies interfering with each
other?

array = Array.new(5) { [1,2,3] }

 

[Brian Schröder]

Been looking this up in the myriad of deepcopy strands, but couldn't
find it in 30 minutes, so I'm posting the question.
=20
The question is simple. What way would you create an array that
contains 5 copies of an array, without the copies interfering with each
other?
=20
array =3D [1,2,3]*5
=20
generates:
[[1,2,3],[1,2,3],[1,2,3],[1,2,3],[1,2,3]]
=20
but unfortunately also makes 'array[1][1] =3D "a"' change it like this:
=20
[[1,"a",3],[1,"a",3],[1,"a",3],[1,"a",3],[1,"a",3]]
=20
---------
Anyway, found a solution during tinkering, although I don't know why.
Thought I'd just still post it anyway.
=20
ar =3D []
5.times{ar << [1,2,3]}
=20
works, and 'array[1][1] =3D "a"' results in the thing I want
=20
[[1,2,3],[1,"a",3],[1,2,3],[1,2,3],[1,2,3]]
=20
=20

For me [1,2,3]*5 behaves different.

irb(main):001:0> [1,2,3]*5
=3D> [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]


For what you want you could use:

irb(main):002:0> a =3D Array.new(5) { [1,2,3] }
=3D> [[1, 2, 3], [1, 2, 3], [1, 2, 3], [1, 2, 3], [1, 2, 3]]
irb(main):003:0> a[1][1] =3D 'a'
=3D> "a"
irb(main):004:0> a
=3D> [[1, 2, 3], [1, "a", 3], [1, 2, 3], [1, 2, 3], [1, 2, 3]]

$ ruby -v
ruby 1.8.2 (2005-04-11) [i386-linux]

Which version of ruby are you using?

best regards,

Brian Schr=F6der

--=20
http://ruby.brian-schroeder.de/

Stringed instrument chords: http://chordlist.brian-schroeder.de/

 

[Premshree Pillai]

For me [1,2,3]*5 behaves different.
=20
irb(main):001:0> [1,2,3]*5
=3D> [1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]

He prolly meant [[1, 2, 3]]*5

--=20
Premshree Pillai