address

address has 2 important properties:

• .balance

• .transfer(amount)

  • cascades exceptions

  • if an exception is triggered in the contract you are calling, typically this exception will cascade and the whole transaction will get cancelled. No state changes will be made.

address myAddress = "0xabc.."

myAddress.balance => balance in wei
myAddress.transfer(wei_amt) => transfer from the smart contract to the address

for usage see function-payable

Low-level calls

• .send -> returns a boolean, does not cascade exceptions.

  • does not cascade exceptions. if exception returns False.

• .call.gas().value()()

  • let's you forward a specific amount of gas.

  • returns boolean

  • you see this in re-entrancy bugs

.send & .transfer both only transfer 2300 gas along

• execution is capped with 2300 gas, to do whatever computation you want.

• this could cause issues if more than 2300 gas is required.