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address public minter;
string name;
int num;
uint constant x = 32**22 + 8;
string constant text = "abc";
bytes32 constant myHash = keccak256("abc");
uint256 ticket = 1 ether;
變數賦值
pragma solidity ^0.4.25;
contract C {
uint[] data;
function f() public view returns (uint, bool, uint) {
return (7, true, 2);
}
function g() public {
// 聲明和分配變數。 明確指定類型是不可能的。
var (x, b, y) = f();
// 分配給一個預先存在的變數。
(x, y) = (2, 7);
// 互換值的常用技巧對於非價值存儲類型不起作用。
(x, y) = (y, x);
// 組件可以省略（也可以用於變數聲明）。
// 如果元組以空組件結束，其餘的值將被丟棄。
(data.length,) = f(); // 設置長度為 7
// 在左邊也可以做同樣的事情。
(,data[3]) = f(); // Sets data[3] to 2
// 組件只能在作業的左側排除，但有一個例外：
(x,) = (1,);
// (1,) 是指定1元組元的唯一方法，因為（1）等於1。
}
}
block.blockhash(uint blockNumber) returns (bytes32): hash of the given block - only works for 256 most recent blocks block.coinbase (address): current block miner’s address block.difficulty (uint): current block difficulty block.gaslimit (uint): current block gaslimit block.number (uint): current block number block.timestamp (uint): current block timestamp msg.data (bytes): complete calldata msg.gas (uint): remaining gas msg.sender (address): sender of the message (current call) msg.value (uint): number of wei sent with the message now (uint): current block timestamp (alias for block.timestamp) tx.gasprice (uint): gas price of the transaction 6.4. Solidity in Depth 99Solidity Documentation, 0.4.10 tx.origin (address): sender of the transaction (full call chain) revert(): abort execution and revert state changes keccak256(...) returns (bytes32): compute the Ethereum-SHA-3 (Keccak-256) hash of the (tightly packed) arguments sha3(...) returns (bytes32): an alias to keccak256() sha256(...) returns (bytes32): compute the SHA-256 hash of the (tightly packed) arguments ripemd160(...) returns (bytes20): compute the RIPEMD-160 hash of the (tightly packed) arguments ecrecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) returns (address): recover address associated with the public key from elliptic curve signature, return zero on error addmod(uint x, uint y, uint k) returns (uint): compute (x + y) % k where the addition is performed with arbitrary precision and does not wrap around at 2**256 mulmod(uint x, uint y, uint k) returns (uint): compute (x * y) % k where the multiplication is performed with arbitrary precision and does not wrap around at 2**256 this (current contract’s type): the current contract, explicitly convertible to address super: the contract one level higher in the inheritance hierarchy selfdestruct(address recipient): destroy the current contract, sending its funds to the given address .balance (uint256): balance of the Address in Wei .send(uint256 amount) returns (bool): send given amount of Wei to Address, returns false on failure .transfer(uint256 amount): send given amount of Wei to Address, throws on failure
block.blockhash(uint blockNumber) returns (bytes32): 某個區塊的區塊鏈hash值
block.coinbase (address): 當前區塊的挖礦地址
block.difficulty (uint): 當前區塊的難度
block.gaslimit (uint): 當前區塊的gaslimit
block.number (uint): 當前區塊編號
block.timestamp (uint): 當前區塊時間戳
msg.data (bytes): 參數數據
msg.gas (uint): 剩餘的gas
msg.sender (address): 當前發送消息的地址，執行合約的地址。
msg.sig (bytes4): 方法ID
msg.value (uint): 執行合約時，轉賬的eth數量，以wei為單位。
now (uint): 時間戳，等價于block.timestamp (uint)
tx.gasprice (uint): 交易的gas單價
tx.origin (address):交易發送地址