Linked Questions
11 questions linked to/from Why does uint8 cost more gas than uint256?
1
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0
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Why is creating a uint8 more expensive than a uint256? [duplicate]
Assume a contract:
contract A {
function b() constant returns (uint8 result) {
result =1;
}
}
When I replace uint8 result with uint256 result then the creation of the contract gets ...
- 11.7k
13
votes
3
answers
17k
views
What uint type should be declared for unix timestamps?
I try to specify uint type to uint16 instead of just doing uint or uint256 when dealing with time stamps but it says that I must use at least uint24. It works with uint24, but shouldn't uint16 be ...
- 1,375
11
votes
1
answer
13k
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Testing Error thrown with hardhat
How would you test the following function with solidity v0.7 and hardhat v2.3.3?
function myFunction(int8 _num) public {
require(_num > 5, "Num should be bigger than 5");
....
- 267
8
votes
3
answers
5k
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Type casting msg.value to uint248
I am new to solidity programming and sorry if my question is very basic.
I am wondering if we can cast msg.value to uint248
Example below ;
uint value;
value = (uint248) (msg.value);
- 241
4
votes
2
answers
3k
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Initialize a fixed size, 2 dimensional array within function
In Solidity, how do I define a fixed size, 2 dimensional uint8 array scoped to a function, initialized with all zeros?
E.g.
func(){
var myArr = new uint8[5][5](); // which does not work.
}
- 213
4
votes
1
answer
1k
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Why time values should be used as uint256?
Is there a reason to use the time value as uint256?
Is not uint128 enough?
UnixTime...
- 75
7
votes
2
answers
2k
views
Use uint40 for time in Solidity?
My question is: Should I use uint40 for time in Solidity?
All the examples I've seen use uint256 for time, however, I think it's too wasteful -- while using uint32 is maybe a little aggressive due to ...
- 371
2
votes
1
answer
863
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Is it better practice to use smaller uint sizes when applicable?
My understanding of uint sizes is that smaller sizes will decrease gas costs. In my current dapp I'm building, I am dealing with time, for which it seems that uint32 will be plenty for my purposes (...
3
votes
2
answers
182
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Are storage variables tightly packed like struct fields?
Tight variable packing is a known coding pattern in Solidity for saving gas by placing struct fields that are lower than 256 bits closer to one another.
Does this logic apply to storage variables? ...
- 18.7k
0
votes
1
answer
295
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Why does Uniswap use Q notation versus the uint256 ratio price?
Question:
Why does Uniswap use Q notation versus the uint256 ratio price? A price in uniswap is always in token1/token0. Which token is which depends on the hex value assigned by the contract address ...
- 299
1
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0
answers
79
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Store constants as non-256 bit fields
My contract has a lot of uint256 constant fields that are later used for various calculations. I am close to reaching the maximum allowed contract size and I am looking for optimizations.
I see that ...
- 177