在一行中创建多个数组

I need to do something like the following

我需要做如下的事情。

e = []
m = []
p = []
t = []
...and so on for about 10 different arrays

Is there a way to create all these arrays on one line?

有办法在一行中创建所有这些数组吗?

4 个解决方案

#1

You can do it using the following:

你可以使用以下方法:

e,m,p,t... = Array.new(10) { [] }

It turns out

事实证明

[[]]*10

is not the right way to go, [[]]*10 is for repetition and is just repeating the same object [] 10 times, so all the variables would end up getting assigned to the same object.

不是正确的方法，[]*10是重复的，只是重复相同的对象[]10次，所以所有的变量最终会被分配给相同的对象。

#2

Like multiple variable declaration in one line a1, a2, a3 = 3, 10, 4

就像一行a1 a2 a3 = 3,10,4中的多重变量声明

e, m, p, t ... = [], [], [], [] ...

#3

I'm curious at what are those 10 different arrays, because I would suspect they shouldn't be 10 different variables but just one. You don't give any context, so I can only guess, something like the following might better:

我很好奇这10个不同的数组是什么，因为我觉得它们不应该是10个不同的变量，而应该是1个。你没有提供任何背景，所以我只能猜测，以下这样的东西可能更好:

whatever = Hash.new{|h, k| h[k] = []}
whatever[:e] # => []
whatever[:m] << 42
whatever[:m] # => [42]
# etc...

Otherwise, as zomboid wrote:

否则,正如zomboid写道:

e, m, p, t ... = [], [], [], [] ...

#4

What all fails

什么都没有

>  p, q, r = v = Array.new(3, [])
 => [[], [], []] 
>  v.map(&:object_id)
 => [70155104393020, 70155104393020, 70155104393020] 
>  p = q = r = []
 => [] 
>  [p, q, r].map(&:object_id)
 => [70155104367380, 70155104367380, 70155104367380]

What works

什么工作

>  p, q, r = v = Array.new(3){ [] }
 => [[], [], []] 
>  v.map(&:object_id)
 => [70155104731780, 70155104731760, 70155104731740]

#1