package flatten

// FlattenArray flattens the array input, and places inputues into the array output
// When a nested array is encountered, FlattenArray will recurse into itself
//
// In the case that an element in input is not either int or []int, FlattenArray returns nil
func FlattenArray(input []interface{}) []int {
	var output []int
	for _, val := range input {
		switch i := val.(type) {
		case int:
			output = append(output, i)
		case []interface{}:
			output = append(output, FlattenArray(i)...)
		default:
			return nil
		}
	}
	return output
}