How do you convert a txt file of numbers into a 2D array in lua?

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I have a txt file with numbers in this pattern:

3 2 1 3
4 5 9 4
2 3 4 2
2 3 4 5

I have to read this data and convert it into a suitable data structure. This all needs to be done in Lua and I am quite brand new to the language. Please assist?

What I have tried:

The only thing I was able to do was to open, read and display the file but cannot store its data into a suitable data structure.

a = io.open ("grid.txt", "r")
io.input (a)
print(io.read("*all"))
io.close()

Posted 9-Dec-22 2:35am

Rkut

Updated 10-Dec-22 7:58am

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Richard MacCutchan · Answer 1 · 2022-12-09T03:08:00

Solution 1

If you are brand new to a language then the best place to start is at the language home page: The Programming Language Lua[^].

Posted 9-Dec-22 3:08am

Richard MacCutchan

CPallini · Answer 2 · 2022-12-10T07:58:00

Try

Lua

local f = io.open("grid.txt")
assert(f, "unable to open the file")

-- collect the array
local arr = {}
for l in f:lines() do
  local row = {}
  for snum in l:gmatch("(%d+)") do
    table.insert(row, tonumber(snum))
  end
  table.insert(arr, row)
end

-- show the collected array
for i=1,#arr do
  for j=1,#arr[i] do
    print( string.format("arr[%d][%d] = %d", i, j, arr[i][j]))
  end
end