合約部署

• 編寫一個簡單的智慧合約

pragma solidity 0.4.19;  
contract hello {  
function main(uint a) constant returns (uint b)   
    {  
        uint result = a * 8;  
        return result;  
    }  
}  

• 編譯後

var helloContract = web3.eth.contract([{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"main"
 
,"outputs":[{"name":"b","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]);
var hello = helloContract.new(
   {
     from: web3.eth.accounts[0], 
     data: '0x6060604052341561000f57600080fd5b60b68061001d6000396000f300606060405260043610603f576000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063ab3ae255146044575b600080fd5b3415604e57600080
 
fd5b606260048080359060200190919050506078565b6040518082815260200191505060405180910390f35b600080600883029050809150509190505600a165627a7a723058203f6d4f506de85c5287b58705788b98694a2b14b17fd6db0c376260b4a0b5a7a00029', 
     gas: '4700000'
   }, function (e, contract){
    console.log(e, contract);
    if (typeof contract.address !== 'undefined') {
         console.log
 
('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
    }
 })

將上面程式碼複製進控制檯

此操作請在miner.start()情況下進行

呼叫智慧合約

$ hello.main.call(100)
800