Linked Questions
22 questions linked to/from How do gas refunds work?
0
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2
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How are gas refunds "payed"? [duplicate]
I have a doubt about the gas refund concept.
Imagine that I created a smart contract 1 month ago and now I want to call the SELFDESTRUCT
because I want to send the current balance to an address and ...
- 259
1
vote
1
answer
75
views
If gas is refunded, is it required to call? [duplicate]
Suppose a smart contract external function uses very much gas, but refunds (with .transfer()) the used gas to the caller.
Question: Can it be called with a small amount of gas despite it uses much?
...
- 1,744
40
votes
3
answers
15k
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Difference between Memory and Storage?
What is the difference between Memory and Storage ?
From both the EVM point of view and the contract design one.
Thanks!
- 1,135
23
votes
2
answers
3k
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What type of operations have negative gas costs?
I understand that some operations cost negative gas because they free up space on the blockchain, such as selfdestructs. What are all the operations that can have negative gas? Does this only occur ...
- 656
18
votes
1
answer
8k
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How to clear large arrays without blowing the gas limit?
As posted by redditor ethererik in the post GovernMental's 1100 ETH jackpot payout is stuck because it uses too much gas, 1,100 ethers are stuck in limbo because the payout of this GovernMental ...
- 40.2k
15
votes
3
answers
1k
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How come I need to specify a higher gasLimit than estimateGas?
If a contract call predictably requires 41043 of gas to be processed as estimated by estimateGas, how come I need to specify gasLimit of ~70000 to be processed?
- 915
11
votes
1
answer
2k
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Is the cost of updating storage different than the cost of adding to storage?
Do these have a separate cost?
sstore(1, 10) # first time adding a value to storage with this key
sstore(1, 20) # changing the value in storage.
I looked for a list of gas costs / opcodes, and the ...
- 695
6
votes
2
answers
6k
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How can I estimate price of data storage? [duplicate]
I'd like to make estimations of the cost of an application, and one of the things I need is the price to store n kB of data on a contract. In ether and in USD.
Where could I find rates or prices of ...
- 1,516
6
votes
2
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2k
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How to know, inside the contract function, the amount of gas that will be refunded in the end
Consider the following situation: my function can be divided into 2 parts
Always consumes constant gas;
Always results in a refund of 0 < R < 1500000 gas.
After the second part had happened, ...
3
votes
2
answers
1k
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Gas refunds via “Self-destruct” prior to a revert()
In a transaction that eventually calls revert(), if prior to the revert we have SELFDESTRUCT some contracts and thus received a gas refund, does the gas refund also get reverted?
- 93
1
vote
1
answer
2k
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Gas limit issue when transfer USDT
i have been asking by my client to save ETH when transfer out his USDT, he hope there is no or very little ETH left in his new USDT address. Please assume that USDT address has no initial ETH and next ...
- 21
4
votes
1
answer
289
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Rationale Behind Ethereum's Data Storage Scheme
1) Why does Ethereum store data in 32byte chunks? I don't suppose this to be some backward-compatibility left-over; is it? We could store data in variable length fields as well.
2)I don't think ...
- 313
4
votes
2
answers
370
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Understanding the formal description of a transaction and its associated refunds
Excerpt from page 8 of the yellow paper:
I fully understand that contracts can self-destruct and, when that happens, according to this thread, all the balance is refunded to the address specified as ...
- 17.3k
5
votes
1
answer
138
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Is it possible to use negative gas to execute a Reentrant attack using .send()?
Haven't tested it out but I think in theory this could work. It might work somehing like this:
An attacker first writes a lot of data to storage so there is data to be deleted.
Using .send() in the ...
- 667
0
votes
3
answers
376
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Is there any alternative for for loop?
I have used in burn() function of NFT Contract.
function burn(address to, uint256 tokenId) external {
require(_exists(tokenId), "Contract: operator query for nonexistent token");
...
