Accessibility.sol

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

contract Accessibility {
    uint public publicInt;
    uint internal internalInt;
    uint private privateInt;

    uint externalInt; // for external function

    constructor() {
        publicInt = 1;
        privateInt = 1;
        internalInt = 1;
        externalInt = 1;
    }

    function publicFunction() public {
        publicInt += 1;
    }

    function privateFunction() private {
        privateInt += 1;
    }

    function externalFunction() external {
        externalInt += 1;
    }

    function internalFunction() internal {
        internalInt += 1;
    }

    function callExternalFunction() public {
        this.externalFunction();
    }

    function print() public view returns(uint _privateInt, uint _publicInt, uint _internalInt, uint _externalInt) {
        return (privateInt, publicInt, internalInt, externalInt);
    }
}

contract AccessPublic {
    Accessibility accessibility = new Accessibility();

    function accessPublicInt() public view returns(uint) {
        uint publicInt = accessibility.publicInt();
        return publicInt;
    }
}