Questions tagged [struct]
Question about the solidity Structs
231
questions
2
votes
1answer
19 views
What size is an enum member inside of a struct
Let's consider the following code:
pragma solidity ^0.4.18;
contract Test {
enum EnumTest {
Test0,
Test1
}
struct StructTest {
EnumTest Foo;
uint256 Bar;
}
}
Not taking ...
1
vote
1answer
38 views
Vyper mapping inside a struct
Is it possible to have a mapping inside a struct for vyper? For example:
struct Teddy:
id: uint256
year: uint256
component: map(uint256, uint256)
teddies: private(map(uint256, Teddy))
...
0
votes
1answer
33 views
How to save data using multiple structures and arrays in solidity?
How can i use multiple arrays please?
e.g: I have this contract:
pragma solidity >=0.4.21 <0.6.0;
contract SessionManagement {
struct ChargeProfileSegment{
uint startDateTimeSeg;...
1
vote
1answer
45 views
VM error: revert. revert The transaction has been reverted to the initial state. Note: The called function should be payable if
Hi Guys 👋
I have two contacts first one is SubToken and second one is MainContract.
First I deploy MainContract after that I use createNewContract function and I create new SubToken.
and then
I ...
1
vote
1answer
19 views
Trouble accessing an array inside a struct inside a mapping via web3
Here are a few relevant code snippets from my smart contract
struct Constituency{
uint16 id;
string name;
uint64[] cans;
}
mapping(uint => Constituency) public constituencies;
...
1
vote
1answer
31 views
Are memory variables initialized by solidity?
I've the following struct
struct Vote {
uint amount;
uint count;
}
Is it initialized when allocated in memory?
function boofar(uint val) public {
Vote memory result;
result.amount += val;
}
...
0
votes
3answers
22 views
Struct creates instances with zero values for all of it properties instead of using function arguments
Inside my smart contract I have a struct type NotaryEntry and a function addNotaryEntry which creates an instance of the struct and add to a mapping, I do pass the right values to the function but the ...
0
votes
1answer
23 views
Return an array of structs using events?
I wan’t my function to spit out an array of structs. I know this is not straightforwardly possible. What is the best way for me to proceed? Should I loop through my array in my function and trigger ...
0
votes
1answer
42 views
Member “name” not found or not visible after argument-dependent lookup in string storage ref
I have code like this and I want to set my name, surname and age in my struct so I want to set them and get them using with my functions
here's my code :
pragma solidity >=0.4.0 <0.7.0;
...
1
vote
1answer
47 views
Which is faster: loop inside contract or loop of transactions?
I have this contract:
pragma solidity 0.5;
pragma experimental ABIEncoderV2;
contract TestStruct {
struct User {
string name;
uint256 age;
}
mapping (bytes32 => ...
0
votes
3answers
112 views
ParserError: Expected ',' but got identifier
pragma solidity >=0.4.0 <0.7.0;
contract NewHello{
struct kullanicilar{
string name;
string surname;
uint age;
}
event infoChanged(
string name,
...
1
vote
1answer
53 views
How to pass struct params in remix ide?
I have this smart contract:
pragma solidity 0.5;
pragma experimental ABIEncoderV2;
contract TestStruct {
struct User {
string name;
uint256 age;
}
mapping (bytes32 =&...
0
votes
1answer
72 views
Type string memory is not implicitly convertible to expected type struct InsanFactory.User storage ref
pragma solidity >=0.4.0 <0.7.0;
contract InsanFactory{
struct User{
string name;
address myaddress;
}
mapping(address => User) public userStructs;
...
1
vote
0answers
44 views
How to pass a struct as an argument in call using web3.py
Following is a working code on remix. It is recommended to use memory keyword for the struct parameter.
Please also see: Solidity Storage Array Bugs
Which does not work on Web3.py and gives the ...
3
votes
2answers
46 views
returning the struct value in smart contract and experimental ABIEncoderV2
I am storing and returning the struct value by using mapping.
pragma solidity >=0.5.0 <0.7.0;
pragma experimental ABIEncoderV2;
contract Manage{
struct Policy{
string PolicyID ;
}
...
0
votes
1answer
25 views
Web3 event listener - timing issue when immediately retrieving contract values
I'd like to be able to immediately get a struct value from a mapping after calling a function that updates the struct, however, when testing with Ganache, sometimes the event arrives to the listener ...
0
votes
2answers
56 views
How to access content of mapping in a struct?
I'm aware of this post:
Accessing a mapping within a struct via Truffle console
However, it seems to me, it does not provide a clear answer. Also, my question is more generic and not just for ...
0
votes
1answer
30 views
Initialize an array of struct within a struct
I am working on a use case of "Purchase Order" wherein there will be multiple Products listed/ordered under one Purchase Order(PO) by a buyer.
1 PO : N Products
struct Product{
bytes32 ...
0
votes
1answer
20 views
Storing geo location in contract
I am beginner in solidity programming, I am trying to write my first contract. I am trying to store a piece of land (which is array of coordinates) against a person. I am having trouble storing the ...
0
votes
1answer
22 views
How can I pass struct as function parameter with ABIEncoderV2 from outside?
have this code:
struct UserScore {
address user;
uint score;
uint time;
}
function getWithStruct(UserScore _user) public view returns (address, uint, uint) {
return (_user.user, _user....
0
votes
1answer
77 views
How can I send array of structs as arguments?
I want to send to my contract an array of currency and its price so it will store it:
pragma solidity ^0.4.24;
contract ExchangeContract {
enum CurrencyType { USD, TWOKEY, BTC, ETH, DAI, USDT, ...
0
votes
0answers
12 views
How to return a struct which contains another struct?
I'd like to return a struct which contains another struct.
When calling the function, I want to make the return result likely to
0:string: Username
1:string[]: [[a.doc,...
1
vote
1answer
46 views
Struct member access in web3 requires additional dummy field
If a struct contains a single field, then that field is inaccessible from web3. In the below example, field uint b must also be present in order to access field uint c from web3.
Of course, it's not ...
2
votes
3answers
98 views
Should I use require in view functions?
When I call a solidity function to get a struct element, is it a best practice to use require and check if the element exists or should I just return the empty values?
Without require:
function ...
0
votes
0answers
71 views
How should I pass a nested struct as a function argument in Remix IDE?
Example contract:
pragma solidity ^0.4.24;
pragma experimental ABIEncoderV2;
contract someContract {
struct structOne {
uint a;
}
struct structTwo {
uint b;
...
0
votes
2answers
251 views
Default getter and setter for mapping in solidity
In my smart contract I've public mapping as mapping (uint=>User) public users where User is a Struct, so is there any way to get the values of this mapping using default getter.
For Example : If ...
0
votes
1answer
141 views
Invalid type for argument in function call. Invalid implicit conversion from mapping
I have defined struct for saving data to ethereum blockchain. I am using uint to map the data stored with a unique ID. I am using truffle framework to write smart contracts with solidity version: 0.4....
1
vote
1answer
16 views
Use Values Returned from One Function in Another
need a little help if you can spare the time.
Making a little card game where people can collect "warrior" cards.
We'll have an initial 12 master "cards" that supply the initial traits for the ...
0
votes
1answer
51 views
Pushing a stuct into an array
What i am attempting to do is elementary, adding a struct to a storage array. But for some reason I am getting the following error
TypeError: Indexed expression has to be a type, mapping or array (...
0
votes
1answer
23 views
Read storage struct from a modifier
If i read a struct(storage) Human storage human = humans[2]; in my modifier is there a possibility that the function that uses this modifier can use the "human"? Otherwise i have to scope the storage ...
2
votes
1answer
46 views
Passing in an array of complex structs
I am wondering what pattern I am supposed to follow in Solidity to take in an array of structs as a parameter. I am translating code from CPP and mostly everything translates directly besides this (...
1
vote
1answer
69 views
Can I modify a struct property and send it back to the contract?
we are experiencing an issue dealing with structs.
We expect to modify a struct property after getting it from an event in web3js, but, it seems that the modify does not apply.
Any ideas?
Contract ...
2
votes
2answers
385 views
Passing Struct as an argument in call
I am trying to pass a struct as an argument while calling the function of another contract:
pragma solidity ^0.4.24;
pragma experimental ABIEncoderV2;
library Test {
struct TStruct {
int x;
...
1
vote
1answer
216 views
UnimplementedFeatureError: Encoding type “struct BiddingContract.Bidder memory” not yet implemented
The code is broken with the new upgrade v0.5,
using
Truffle v5.0.1 (core: 5.0.1)
struct Bidder {
address bidders_address;
uint productId;
uint bidValue;
}
struct Product {
uint ...
0
votes
2answers
209 views
access mapping inside mapping of struct in Solidity ^0.5.0
I have a contract which looks like this:
contract a {
struct Str {
uint256 totalTokens;
mapping(address => uint256) playerTokens;
}
mapping(uint256 => Str) public ...
1
vote
0answers
322 views
Check if a struct is empty
I have a function where I pass a id. With that id the contract find in a mapping a struct. My idea is to check if exists that struct with the given id with a if clause.
I try with 0, null, "".
Is ...
0
votes
1answer
41 views
Associate event struct to user addresses
I have two contracts. One called User and other called Event
pragma solidity ^0.4.24;
contract User {
mapping(uint=>address) addresses;
uint addressRegistryCount;
}
pragma solidity ^...
1
vote
0answers
58 views
How can I pass struct from one contract to another?
I have two contracts and I'm trying to pass the struct data from one to another, I can do this by creating a mapping and having a uint input associated with that struct but I'd like to get the struct ...
0
votes
1answer
24 views
Struct and Mapping input value error of Invalid Opcode while calling setSeller() to store multiple seller's addresses
What dose the -1 means? Or why we should use -1 while pushing one element in array. What should I enter in sellerAccounts: field as input?
pragma solidity ^0.5.1;
contract Seller{
struct ...
0
votes
1answer
67 views
Making a contract with new keyword address is always 0x0000000000000000000000000000000000000000
I'm making a contract that makes other contracts. Once the contract is made using address tokenAddress = new MyToken('Name'); I want to save the address of the contract, tokenAddress, in MyStruct. ...
0
votes
1answer
80 views
Access modifiers for properties of a struct
I am relatively new to Solidity. I am following a tutorial and came up with the following contract:
contract Election {
struct Candidate {
uint id;
string name;
uint voteCount;
}
...
0
votes
1answer
29 views
Array of struct inside and a array
It´s posible to save structs inside array and all this array´s inside the same array. I mean:
[ [{"struct"}, {"struct"}, {"struct"}], [ {"struct"}, {"struct"}], [{"struct"}, {"struct"}, {"struct"}, {"...
4
votes
2answers
94 views
Why is the Eternal Storage approach still used if it hugely increases gas usage compared to storing data in structs?
I was wondering why is the eternal storage approach (first code snippet) still used? I know it's meant to make contracts upgradable but it seems too expensive to me.
contract Storage {
mapping(...
1
vote
1answer
268 views
Nested structs that are part of a mapping broken in Solidity 0.5.0?
The following code compiled successfully with Soldity 0.4.21. With 0.5.0 it triggers a fatal compilation error as follows:
UnimplementedFeatureError: Encoding type "struct TestNestedStructInMapping....
1
vote
2answers
30 views
Can I instantiate a struct with a member struct without supplying a member struct?
I have a struct containing another struct. The member struct does not yet exist when instantiating the containing struct. Is there a default for a struct (for address, int, etc' I would initialize ...
0
votes
1answer
117 views
Is there any way to return multiple structs (or the fields from them) in Solidity when one of the struct fields is of type `bytes`?
I would like to return structs keys from my contract to display on the frontend, ideally 10 at a time. I understand that if I make keyByOwner public I can return a single key at a time with the getter ...
1
vote
1answer
94 views
Set just a couple of parameters in a Struct
I have a struct with 10 parameters. The idea is to apply this struct for represent the flow of a trace. So I have to set variables values in a stepped way. Now i´m trying to call a function to set the ...
0
votes
1answer
14 views
Struct param not found
I´m trying to call a function insertOrigin inside a struct and then call other function getOrigin to return that values. But VS Code get a error
pragma solidity ^ "0.4.24";
contract Origin {
struct ...
0
votes
1answer
193 views
How can return a struct from a function [duplicate]
I have one solidity file, inside that file I have a this function:
struct OriginInfo{
string 1;
uint32 2; //In timestamp
uint8 3;
address 4;
bool 5;
}
function insertOrigin(...
0
votes
1answer
124 views
How to initialize a new struct with an empty mapping? [duplicate]
For expl.
mapping(uint => Test) tests;
struct Test {
uint id;
mapping(address => uint) votes;
}
function newTest() public {
test[0] = Test(0, <EMPTY_MAPPING>)
}
