flatternDeep and flattern

by Evgeniy Kvasyuk

JavaScript

const flattern = array => {
	if (!Array.isArray(array)){ 
  	return []; 
  }
  return array.reduce((acc, current) => Array.isArray(current) ? [...acc, ...current] : [...acc,  current], []);
}

const flatternDeep = (array) => {
	if (!Array.isArray(array)){
  	return []; 
  }
  return array.reduce((acc, current) => Array.isArray(current) ? [...acc, ...flatternDeep(current)] : 	[...acc, current], []);
}

console.log(flattern([1, 2, 3, [4, 5, 6]]));

console.log(flatternDeep([5,2,3,
    	[5,5, [4,4,4,4]], 4, 6
    ]
  )
);