function flatten(array) {
  // Ваш код здесь
}
 
console.log(flatten([[1], [[2, 3]], [[[[[4]]]]]])); // -> [1, 2, 3, 4]

const arr = [[1], [[2, 3]], [[[4]]]];
 
function flatten(arr) {
  return arr.flat(Infinity);
}
 
console.log(flatten(arr)); // -> [1, 2, 3, 4]

function flatten(array) {
  let newArr = [];
 
  for (let name of array) {
    if (Array.isArray(name)) {
      newArr = newArr.concat(flatten(name));
    } else {
      newArr.push(name);
    }
  }
  return newArr;
}
 
console.log(flatten([[1], [[2, 3]], [[[[[4]]]]]])); // -> [1, 2, 3, 4]