Multidimensional Arrays and the Push Function

[Ezki11]

Hello, I've been having trouble trying to push variables in 2 dimensional arrays. I don't even know if this is possible.

The first thing I do is initialize the array like so:

array2=Array.new(3){Array.new}

Next, I have two other variables, for example:

var1=3
var2=rand(10)

So what I'm trying to do is to push the array that is inside the array.

for x in 0...var1
   for i in 0...var2
      array2[x].push[i]=rand(50)
   end
end

However, this isn't working. Can you use the push function in 2 dimensional arrays? Or is the problem elsewhere?

 

[mej71]

push is a method to act on an array, you've got your syntax wrong

for x in 0...var1
   for i in 0...var2
      array2[x][i].push(rand(50))
   end
end

However, this is still wrong. You've only got a two level array here
(looks like)

[
    [1,2,3,4,5],
    [1,2,3,4,7],
    [1,2,3,4,5]
]

So your original code is also trying to use the push method on a member of the sub-array, not the array itself

for x in 0...array2.size  #var1 is uneccessary, since array2's size may change
    var2.times {array2[x].push(rand(50)) }
end

 

[Ezki11]

push is a method to act on an array, you've got your syntax wrong

for x in 0...var1
   for i in 0...var2
      array2[x][i].push(rand(50))
   end
end

However, this is still wrong. You've only got a two level array here
(looks like)

[
    [1,2,3,4,5],
    [1,2,3,4,7],
    [1,2,3,4,5]
]

So your original code is also trying to use the push method on a member of the sub-array, not the array itself

for x in 0...array2.size  #var1 is uneccessary, since array2's size may change
    var2.times {array2[x].push(rand(50)) }
end

Ah, I see. I've been running a few tests on some Ruby editors and yeah, I see that now. Thanks for clearing that up!

 

[MysteriousUser94]

You can also init your array like this :

array2 = Array.new(3) { Array.new(rand(10)) { rand(50) } }

PS : You can get the current index of the item while initializing the array like this :

array2 = Array.new(3) { |index_x| Array.new(rand(10)) { |index_y| rand(50) } }

(If you want to put something else than random numbers)