pragma solidity >=0.4.0 <0.7.0;
contract HelloWorld{
    string public stateVariable = "Hello World";
    int int1;

   function GetHelloWorld() public view returns (string  _hello){
        _hello=stateVariable;
    }

}

solidity编译出现： TypeError: Data location must be "memory" for return parameter in function, but none was given.