什么是 Gas
为计算付费
什么是 Gas 是 CoddyKit 上的免费 Web3 & DApp Development Fundamentals 课时。 这是第 1 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Web3 & DApp Development Fundamentals 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Web3 & DApp Development Fundamentals 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Why Computation Costs Money
Every operation on Ethereum runs on thousands of nodes worldwide. To prevent abuse and pay for this work, the network charges gas.
Gas is the unit that measures computational effort.
What Is Gas?
Gas is a unit of measurement for the work required to execute operations on the EVM.
Sending ETH, calling a contract, or storing data each consume a specific amount of gas based on their complexity.
Gas Units per Operation
Different operations cost different amounts of gas. Simple operations are cheap; storage is expensive.
ADD -> 3 gas
MUL -> 5 gas
SLOAD -> 2100 gas (read storage)
SSTORE -> 20000 gas (new storage)
base tx -> 21000 gasGas vs Gas Price
Keep two ideas separate:
- Gas used — how much computation the transaction needs (units)
- Gas price — how much you pay per unit, measured in gwei
Total fee = gas used multiplied by gas price.
Gwei: The Fee Unit
Gas prices are quoted in gwei, a tiny fraction of ETH. One gwei equals one billionth of an ETH (10^-9).
Quoting in gwei keeps numbers readable instead of writing many leading zeros.
1 ETH = 1,000,000,000 gwei
1 gwei = 1,000,000,000 wei
1 wei = smallest unit of ETHCalculating a Fee
The transaction fee is straightforward arithmetic. Multiply the gas your transaction consumes by the price you pay per unit of gas.
gasUsed = 21000
gasPrice = 20 gwei
fee = 21000 * 20 = 420000 gwei
= 0.00042 ETHWhy Gas Exists
Gas serves two purposes:
- Spam prevention — attackers cannot flood the network for free
- Resource pricing — heavy computation costs more, encouraging efficient code
The Halting Problem Solution
Gas also stops infinite loops. Each step consumes gas, and when a transaction runs out, execution halts.
This guarantees the EVM always terminates — you cannot freeze the network with a runaway loop.
while (true) {
// each iteration burns gas
}
// eventually: OUT OF GAS -> revertsWho Receives the Fee?
Gas fees compensate the validators who include and execute your transaction.
Under EIP-1559, part of the fee is actually burned (destroyed), and a smaller tip goes to the validator. We cover this in a later lesson.
Gas and Smart Contracts
Complex smart contract calls cost more gas than simple transfers because they execute many operations.
Efficient contract code directly lowers user costs — gas optimization is a core skill for Solidity developers.
Putting It Together
Gas measures computational work; gas price (in gwei) sets the cost per unit. Their product is your fee.
Gas prevents spam, prices resources fairly, and guarantees execution always terminates.
Quick Check
Test your understanding of gas.
Recap: What Is Gas
You learned that:
- Gas measures computational work on the EVM
- Gas price is paid per unit in gwei
- Fee = gas used multiplied by gas price
- Gas prevents spam and stops infinite loops
Next: the full lifecycle of a transaction.
用 AI 导师学习 Web3 & DApp Development Fundamentals — 免费
在浏览器中编写并运行真实代码，获得全天候 AI 导师的即时帮助，并在网页或应用中继续学习。
- 课程
- 29
- 课程
- 105
常见问题解答
「什么是 Gas」课时是免费的吗？
是的 — 「什么是 Gas」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Web3 & DApp Development Fundamentals 课程的其余内容，请升级到 CoddyKit PRO。 Web3 & DApp Development Fundamentals 课程共包含 4 节课。
「什么是 Gas」这节课中我会学到什么？
为计算付费 你通过在浏览器中直接运行的动手代码来练习 Web3 & DApp Development Fundamentals，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Web3 & DApp Development Fundamentals 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Web3 & DApp Development Fundamentals 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 1 节课，共 4 节。
「什么是 Gas」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Web3 & DApp Development Fundamentals 课中编写并运行代码吗？
能。每节 Web3 & DApp Development Fundamentals 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。