Patterns · easy

11. Modifiers

Reusable access checks.

Create a `modifier onlyOwner()` and apply it to `setValue(uint256)` which writes to `uint256 public value`. Owner is set in constructor to `msg.sender`.

Required in your answer: modifier onlyOwnermsg.sender == owneronlyOwner {_;

Compiles with solc in your browser

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Vault {
    address public owner;
    uint256 public value;
    constructor() { owner = msg.sender; }

    // TODO modifier onlyOwner

    function setValue(uint256 v) external /* TODO onlyOwner */ {
        value = v;
    }
}

Output appears here.

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