I'm trying to create an empty 2d/multidimensional array and then add data to it at specific indexes. Can someone tell me where I'm going wrong?

Struggling to add data to a specific index of a 2D array. I’m quite new to programming so I could have this all completely wrong but any help would be appreciated.

Maybe my declaration of the array is wrong but I am seeing the first pair of [] as the first part where data can be stored, and then the second set inside the first [] is another place where I can store data and this data is linked to the data in the first pair of []

I’m very sorry if I’m not explaining this properly.

void main(){
  var staff = [[]];
  
  int a = 1;
  int b = 2;
    
  staff[0][0].add(b)
  staff[0][1].add(a)
  staff[1][0].add(b)
  staff[1][1].add(a)
  
  print(staff);
}

Ideally I would like an output that looks something like this

[2,1][2,1]

Cheers 😀

>Solution :

Dart is not JavaScript. Arrays (Lists) are not automatically grown when accessing out-of-bounds elements. You must explicitly grow your Lists to have the desired lengths:

void main() {
  var staff = [
    for (var i = 0; i < 2; i += 1)
      [
        for (var j = 0; j < 2; j += 1) 0,
      ],
  ];

  int a = 1;
  int b = 2;

  staff[0][0] = b;
  staff[0][1] = a;
  staff[1][0] = b;
  staff[1][1] = a;

  print(staff); // Prints: [[2, 1], [2, 1]]
}

Alternatively, if you want to grow your Lists dynamically:

void main() {
  var staff = <List<int>>[];

  int a = 1;
  int b = 2;

  staff.add([b, a]);
  staff.add([b, a]);

  print(staff); // Prints: [[2, 1], [2, 1]]
}