[Ethereum] TypeError: Data location must be “memory” for parameter in function, but none was given

From this:

pragma solidity^0.5.0;

contract Contract {
    string public name;

    function Contracts(string passedName) public {
        name = passedName;
    }

    function setName(string newName) public {
        name = newName;

    }

}

To This:

pragma solidity^0.5.0;

contract Contract {
    string public name;

    function Contracts(string memory passedName) public {
        name = passedName;
    }

    function setName(string memory newName) public {
        name = newName;

    }

}

Make sure to use "" to wrap text. Using '' will give you:

transact to Contract.Contracts errored: Error encoding arguments: SyntaxError: JSON.parse: unexpected character at line 1 column 2 of the JSON data

Use memory storage For return struct or array types of data is good practice and it improves the performance of code and from solidity version 0.5.0, it is compulsory to use memory storage for this type of data types.

You have to just put memory keyword in return parameter of function getAdopters() like this:

function getAdopters() public view returns (address[16] memory){

     return adopters;

}