**Problem Statement:**

You are given an integer array `nums`

of length `n`

. The task is to create a new array `ans`

of length `2n`

such that `ans[i] == nums[i]`

and `ans[i + n] == nums[i]`

for `0 <= i < n`

(0-indexed). In simpler terms, the array `ans`

is formed by concatenating two copies of the array `nums`

.

**Solution Approach:**

To solve this problem, we can iterate over the indices of the new array `ans`

, which has a length of `2n`

. At each index `i`

, we assign the value of `nums[i % n]`

to `ans[i]`

. This effectively cycles through the elements of `nums`

twice to fill up the `ans`

array.

Let's break down the steps of the solution:

**Calculate the length of the input array:**First, we determine the length of the input array`nums`

and store it in a variable`n`

.**Initialize an empty array to store the result:**We create an empty array`ans`

where we will store the concatenated array.**Iterate over indices of the new array:**Using a`for`

loop, we iterate over the indices of the new array`ans`

, which ranges from`0`

to`2n - 1`

.**Assign values to the new array:**At each index`i`

, we assign the value of`nums[i % n]`

to`ans[i]`

. Here,`i % n`

ensures that we cycle through the elements of`nums`

.**Return the concatenated array:**Finally, we return the concatenated array`ans`

as the result.

**Python Code with Comments:**

```
from typing import List
class Solution:
def getConcatenation(self, nums: List[int]) -> List[int]:
# Calculate the length of the input array
n = len(nums)
# Initialize an empty array to store the concatenated array
ans = []
# Iterate over indices of the new array
for i in range(2 * n):
# Assign values to the new array
ans.append(nums[i % n]) # Cycling through the elements of nums
# Return the concatenated array
return ans
# Example usage:
# nums = [1, 2, 3]
# solution = Solution()
# concatenated_array = solution.getConcatenation(nums)
# print(concatenated_array)
```

**Conclusion:**

In this post, we've discussed a coding problem that involves concatenating an integer array with itself to create a new array. We've provided a step-by-step explanation of the solution approach and presented the corresponding Python code with comments to help you understand the implementation. I hope this blog post has been helpful in understanding how to solve this problem efficiently in Python. Thank you for reading!