# Filling multidimensional arrays in order in JavaScript

In the previous examples, all the numbers in the subarrays were the same. Let's make the numbers go up now, like this:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

To do this, you need to make a special counter variable that will increase its value by `1` with each iteration of the inner loop. We will write the value of this counter to the array, like this:

`let arr = []; let k = 1; // the counter for (let i = 0; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i].push(k); // write down the counter k++; // increment the counter } } console.log(arr);`

You can simplify the code by incrementing the counter after the assignment:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i].push(k++); } } console.log(arr);`

Please note that in this case, it must be `k++`, and not `++k`, since the second option will first increment the counter, and only then write to the array (that is, as a result, the array will start from two, and not from one), like this:

`[[2, 3, 4], [5, 6, 7], [8, 9, 10]])`

Form the following array using two nested loops:

`[[1, 2], [3, 4], [5, 6], [7, 8]]`

Form the following array using two nested loops:

`[[2, 4, 6], [8, 10, 12], [14, 16, 18], [20, 22, 24]]`

Form the following 3D array using three nested loops:

`[[[1, 2], [3, 4]], [[5, 6], [7, 8]]]`

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; k++; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; let k = 1; for (let i = 0; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; let k = 1; for (let i = 0; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; k--; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; let k; for (let i = 0; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; k++; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0, k++; j < 3; j++) { arr[i][j] = k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++; k++) { arr[i][j] = k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; j++) { arr[i][j] = ++k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; let k = 1; for (let i = 0; i < 3; i++) { arr[k] = []; for (let j = 0; j < 3; j++) { arr[i][j] = k; k++; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

The author of the following code wanted to make such an array:

`[[1, 2, 3], [4, 5, 6], [7, 8, 9]]`

The following code was written for this:

`let arr = []; for (let i = 0, k = 1; i < 3; i++) { arr[i] = []; for (let j = 0; j < 3; k++) { arr[i][j] = k; } } console.log(arr);`

The written code, however, does not do what it was intended. Find and correct the author's mistake.

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