JavaScript, Array Question Answer

Can we do the opposite, get 2-D array from 1-D:

const myArr = [

        [1, 2],

        [3, 4],

        [5, 6]

      ];

      const newArr = myArr.flat();

      console.log(newArr);

Answer: Yes, you can convert a 1D array back to a 2D array. If you want to split a flat 1D array back into 2D, you need to specify the desired number of columns for each inner array (or rows, depending on how you want to divide it). Here’s an example of how to convert the 1D array back to a 2D array with two columns per inner array:

const newArr = [1, 2, 3, 4, 5, 6];

// Function to convert a 1D array to a 2D array

function to2DArray(arr, columns) {

  const result = [];

  for (let i = 0; i < arr.length; i += columns) {

    result.push(arr.slice(i, i + columns));

  }

  return result;

}

const myArr = to2DArray(newArr, 2); // specifying 2 columns

console.log(myArr);

Output:

javascript

Copy code

[

  [1, 2],

  [3, 4],

  [5, 6]

]

In this example, the function to2DArray takes the 1D array and splits it into sub-arrays of length 2. You can adjust the columns parameter to specify the desired number of elements per inner array.