solidity 语法–以太和wei Gas

交易是用以太币支付的。类似于 1 美元等于 100 美分，1 以太币等于 10的18次方 wei。

Transactions are paid with

ether

Similar to how one dollar is equal to 100 cent, one

ether

is equal to 10¹⁸

wei

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

contract EtherUnits {
    uint public oneWei = 1 wei;
    // 1 wei is equal to 1
    bool public isOneWei = 1 wei == 1;

    uint public oneEther = 1 ether;
    // 1 ether is equal to 10^18 wei
    bool public isOneEther = 1 ether == 1e18;
}

Gas:你需要为一笔交易支付多少以太币？你支付的 gas 花费 * gas price 的以太币数量，其中气体是计算单位消耗的气体是交易中使用的气体总量汽油价格是您愿意为每种汽油支付多少以太币具有较高gas价格的交易具有更高的优先级被包含在一个块中。

```
gas
```
is a unit of computation
```
gas spent
```
is the total amount of
```
gas
```
used in a transaction
```
gas price
```
is how much
```
ether
```
you are willing to pay per
```
gas
```
```
gas limit
```
(max amount of gas you're willing to use for your transaction, set by you)
```
block gas limit
```
(max amount of gas allowed in a block, set by the network)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

contract Gas {
uint public i = 0;

    // Using up all of the gas that you send causes your transaction to fail.
    // State changes are undone.
    // Gas spent are not refunded.
    function forever() public {
        // Here we run a loop until all of the gas are spent
        // and the transaction fails
        while (true) {
            i += 1;
        }
    }
}