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contracts...funcintro.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract funcIntro{

    uint age;
    
    function add(uint _x,uint _y) public pure returns(uint){
        return _x + _y;
    }

    function changeAge() public{
        age+=10;
    }
    //getter
    function getAge() public view returns(uint){
        return age;
    }
    //setter
    function setAge(uint _x) public{
        age = _x;
    }

    function func() public{
        //code
    }
}
//we can't change the visibility of outer function of contract....
function demo(uint _x) pure returns(uint){
    //code 
    return _x*10;
}