程式碼示例

pragma solidity ^0.4.4;

contract Mj {

  enum ActionChoices {GoLeft,GoRight,GoStraight,SitStill}
    ActionChoices _choice;
    ActionChoices constant defaultChoice = ActionChoices.GoStraight; //constant定義常量，不能修改。

    function setGoStraight(ActionChoices choice) {
      _choice = choice;
    }
    function getChoice() constant returns (ActionChoices) {
      return _choice; 
    }
    function getDefault() pure public returns (uint)  {
      return uint(defaultChoice); 
    }
}
 

enum是關鍵詞，ActionChoices是自己定義的型別，該型別包含4個引數，當個數在255以為，該型別的資料型別時uint8，超過時為uint16。