Payable Keyword in Solidity
Use Payable as Keyword, not function name
Dec 26, 2017 · Unlisted
First, payable is a modifier that can be added to a function. It's impossible to have payable() as a function name as it is a reserved keyword. You may use payable only in addition to existing functions like:
function deposit() payable {};
function register(address sender) payable {};
function () payable {}Receive Ether from Call Transactions
Second, Payable allows a function to receive ether while being called as stated in docs.It's manadatory from solidity 0.4.x. If you try to send ether using call:
token.foo.call.value("ETH_TO_BE_SENT")("ADDITIONAL_DATA")to a function without a payable modifier, the transaction will be rejected.
Usually, there is a no name function to accept ether to be sent to a contract which is called a fallback function:
function () payable {};But you may have more than one payable annotated functions that are used to perform a different tasks.
Example: How to register deposit to your contract:
function deposit() payable {
deposits[msg.sender] += msg.value;
};