how to read that JSON structure

[farkraj]

Hi, i am not experienced at all in writing/reading json files, hovewer i managed to save my grid in a nested structure but i have no idea how to read it.. i tried but failed miserably multiple times.

my structure looks like this:

{"grid":[[[4],0],[[5],1],[[3],2],[[4],3]}

which means [ [ type ] ID ]

handling jsons is so confusing most of the time i have no idea what im doing thus the problem. Can somebody help and tell me how to get that type and ID from that structure?

 

[FrostyCat]

There is nothing confusing about JSON once you start looking at one depth at a time. Start at the highest depth and collapse everything deeper (i.e. any nested [] or {} structures). Iteratively find out where your target is in the current depth, bubble down, and repeat until you reach it.

Assume that you want to look for the 5 in your sample. You now note that the 5 is somewhere inside the ... filed under "grid".

{"grid": [[[4],0],[[5],1],[[3],2],[[4],3]}
{"grid": ...}

Now consider the next depth. The 5 is inside the second ..., hence you note 1 for its position at this depth.

[[[4],0],[[5],1],[[3],2],[[4],3]
[..., ..., ..., ...]

Inside that, the 5 is inside the first ..., hence you note 0 for its position at this depth.

[[5],1]
[..., 1]

You now have a lone list with a single entry, hence you note 0 for its position at this final depth.

[5]

This gives a sequence of "grid" => 1 => 0 => 0. Assuming that you have already decoded it into json_data:

var five;
five = json_data[? "grid"];
five = five[| 1];
five = five[| 0];
five = five[| 0];
show_message(five); // Shows 5

 

[farkraj]

It kinda works, only when i call it single time and hardcore the numbers. When i try to get ID with the loop it just doesnt work, says it is expecting a number. What do i do wrong? Btw. thanks for in depth explanation, its clearer now but still i have some issues.

for (var i = 0; i < total_tiles; i++)
{
   list = list[| i];
   list = list[| 0];
}

 

[FrostyCat]

That's because you kept digging deeper and deeper without returning back up. You need to go back up before each iteration.

for (var i = 0; i < total_tiles; i++) {
  list = json_data[? "grid"]; // Go back up
  list = list[| i];
  list = list[| 0];
}

 

[farkraj]

Thanks a lot, now it works.