Table read from json file

Solar2D Lua Language
#1

I’m getting a weird result reading a json file back to the table.

Namely, I’m using a not-full two dimensional table (both with indices running from 1 to something) I saved at previous runs of my app, where some values are false, some true and the rest nil. Saved state looks something like this (has more data with it, but I trimmed it):

{"note":[{"2":false,"3":false,"7":true,,"22":false,"23":true},{"1":true,"10":true,"25":false,"26":true},{"27":true,"28":true,"19":true,"11":true},{"17":false,"13":true}]}

When I read it, assign it to my table, and then trying to get, say the value of note[1][22], i get nil. I tried two different approaches at printing a table - one with the pairs() function and the other with usual i=1,n style.

for i, val in pairs(M.note) do     for j, vaj in pairs(M.note[i]) do         print(i, j, M.note[i][j])     end end

With this approach, I get the values printed out corretly, even with correct indices i and j:

1   23   true 1   3    false ... 2   10   true ...

However, using second approach (the lengths of both dimensions are also in the file):

for i=1,M.firstDim do      for j=1,M.secondDim do           print(i, j, M.note[i][j])                          end end

Here, the only value that is printed next to the increasing numbers of i and j, is nil. Why is it this way? Am I missing something?

#2

Try doing
 

for i=1,M.firstDim do for j=1,M.secondDim do print(i, j, M.note[tostring(i)][tostring(j)]) end end

and see if it prints correctly. If that’s the case, it’s reading the “1”, “2” and so on as strings, not as numbers, that’s why they appear correctly with pairs.

#3

Try doing
 

for i=1,M.firstDim do for j=1,M.secondDim do print(i, j, M.note[tostring(i)][tostring(j)]) end end

and see if it prints correctly. If that’s the case, it’s reading the “1”, “2” and so on as strings, not as numbers, that’s why they appear correctly with pairs.