The pop() functions works correctly for normal arrays and mappings.

Based on: [How to delete an element at a certain index in an array?](https://ethereum.stackexchange.com/questions/1527/how-to-delete-an-element-at-a-certain-index-in-an-array)

When I try to pop() an array of a mapping not work.

Any alternative to remove the gaps?

```
pragma solidity ^0.8.0;

// SPDX-License-Identifier:  

contract test {

    mapping (address => uint[]) MyMap;

    constructor(){
        MyMap[msg.sender].push(0);
        MyMap[msg.sender].push(1);
        MyMap[msg.sender].push(2);
        MyMap[msg.sender].push(3);
    }

    //Set last into [2] //1
    MyMap[msg.sender][2] = MyMap[msg.sender][MyMap[msg.sender].length - 1];
    //Delete last array position
    MyMap[msg.sender].pop(); //This line is the problem...

}

```