I need to flatten a multi dimensional array using JS 's flat method. This is the Array [ ["1", "0"], ["3", "5", ["8", ["10"], "11"] ], ]

Question

function flatArrs(arr) {
  let output = arr
    .flat()
    .sort((a, b) => a - b);
  console.log(output);
}

flatArrs([
  ["1", "0"],
  ["3", "5", ["8", ["10"], "11"]],
]);

This is the output and all arrays do not show flattened...why? [ '0', '1', '3', '5', [ '8', [ '10' ], '11' ] ]

Answer 1

flat() takes a depth parameter which specifies how deep to flatten, the default is 1. To flatten to an arbitrary depth you can pass Infinity.

MDN details a number of alternatives, including using concat(), recursivity, and generator functions.

function flatArrs(arr) {
  let output = arr
    .flat(Infinity)
    .sort((a, b) => a - b);
  console.log(output);
}

flatArrs([
  ["1", "0"],
  ["3", "5", ["8", ["10"], "11"]],
]);