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

memoryremixsoliditystorage

/// @dev Adds a new transaction to the transaction mapping, if transaction does not exist yet.
/// @param destination Transaction target address.
/// @param value Transaction ether value.
/// @param data Transaction data payload.
/// @return Returns transaction ID.
function addTransaction(address destination, uint value, bytes data)
    internal
    returns (uint transactionId)
{
    transactionId = transactionCount;
    transactions[transactionId] = Transaction({
        destination: destination,
        value: value,
        data: data,
        executed: false
    });
    transactionCount += 1;
    Submission(transactionId);
}

In In function addTransaction(address destination, uint value, bytes data)

With underlined the byte data parameter

Best Answer

As of Solidity 0.5.0. https://solidity.readthedocs.io/en/v0.5.0/050-breaking-changes.html

Explicit data location for all variables of struct, array or mapping types is now mandatory. This is also applied to function parameters and return variables. For example, change uint[] x = m_x to uint[] storage x = m_x, and function f(uint[][] x) to function f(uint[][] memory x) where memory is the data location and might be replaced by storage or calldata accordingly. Note that external functions require parameters with a data location of calldata.

You can fix it by saying memory for the bytes argument which is an array of byte. 

pragma solidity 0.5.0;

contract Memory {
    function addTransaction(address destination, uint value, bytes memory data)
        internal
        returns (uint transactionId)
    {
        return 0;
    }
}

Warnings are safe to ignore. I wanted to keep this example as close as possible to the original and confirm it compiles.

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