On test network, use a faucet to get ETH.
1 wei 10^18 For a transaction, its always wei who is send
can use web3 towei/fromwei function to convert wei to eth
to verify : object.c[0] it's betster to use object.toNumber() to get the value
important to add payable if we want to get money from the transaction. could be any amount.
constructor function in solidty have the same name than the contract
a fallback function just interecept any transfer to the contract and execute
fallback function can take at max 2300 gas :
- no writing at storage
- no calling external function
- no send ether...