What is meant in this tutorial when it says that using throw will "consume all provided gas"?

Question

When reading the solidity documentation (http://solidity.readthedocs.org/en/latest/solidity-by-example.html#voting), I came across this:

function giveRightToVote(address voter)
{
    if (msg.sender != chairperson || voters[voter].voted)
        // `throw` terminates and reverts all changes to
        // the state and to Ether balances. It is often
        // a good idea to use this if functions are
        // called incorrectly. But watch out, this
        // will also consume all provided gas.
        throw;
    voters[voter].weight = 1;
}

In particular, this part:

But watch out, this will also consume all provided gas.

Does this mean that, if you provide a large amount of excess Ether that it won't be refunded after a throw?

Answer 1

Does this mean that, if you provide a large amount of excess Ether that it won't be refunded after a throw?

Close. It means if you provide a large amount of excess GAS that the gas won't be refunded. For example, maxGas is about USD 1.20 right now, and if you sent maxGas all $1.20 would be consumed. (That's about 0.094 ether)

Throw aborts the transaction, so any Ether sent won't actually get sent.

Gas is what is used to fund the transaction. The actual state of the system other than Gas charges is unchanged if the transaction aborts.