ethereum - Solidity:函数中返回参数的数据位置必须为 "memory"或 "calldata"

Question

我正在学习 Ethereum dev 并尝试运行一个简单的 HelloWorld 程序，但遇到以下错误:

Data location must be "memory" or "calldata" for return parameter in function, but none was given.

这是我的代码:

pragma solidity ^0.8.5;

contract HelloWorld {
  string private helloMessage = "Hello world";

  function getHelloMessage() public view returns (string){
    return helloMessage;
  }
}

Answer 1

您需要返回 string memory而不是 string .
例子:

function getHelloMessage() public view returns (string memory) {
    return helloMessage;
}

memory关键字是变量 data location .