Mixing
How to map an address with a string array in solidity?
Clash Royale CLAN TAG#URR8PPP
up vote
1
down vote
favorite
Goal: I wish to store an array of names with an address in a smart contract. It's more like Key-Value pairs where addresses are paired with a list of type strings.
Can I use mapping to implement this? See below for instance.
mapping(address => strings) userAddress2UserNames;
Or, there is a different approach to it?
Experiments I performed
I got no error when I compiled the above code but when I call a method which returns string from this mapping I got an error stated below.
TypeError: This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.
I'm not much aware of this version but I am assuming I should not do production level implementation with it because may be it's not stable. (Please correct me if I am wrong)
Please suggest me a way to achieve my goal.
solidity arrays mapping solidity-best-practices solidity-design-patterns
asked 7 hours ago
Gagan
737
add a comment |Â
up vote
1
down vote
favorite
Goal: I wish to store an array of names with an address in a smart contract. It's more like Key-Value pairs where addresses are paired with a list of type strings.
Can I use mapping to implement this? See below for instance.
mapping(address => strings) userAddress2UserNames;
Or, there is a different approach to it?
Experiments I performed
I got no error when I compiled the above code but when I call a method which returns string from this mapping I got an error stated below.
TypeError: This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.
I'm not much aware of this version but I am assuming I should not do production level implementation with it because may be it's not stable. (Please correct me if I am wrong)
Please suggest me a way to achieve my goal.
solidity arrays mapping solidity-best-practices solidity-design-patterns
asked 7 hours ago
Gagan
737
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
Goal: I wish to store an array of names with an address in a smart contract. It's more like Key-Value pairs where addresses are paired with a list of type strings.
Can I use mapping to implement this? See below for instance.
mapping(address => strings) userAddress2UserNames;
Or, there is a different approach to it?
Experiments I performed
I got no error when I compiled the above code but when I call a method which returns string from this mapping I got an error stated below.
TypeError: This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.
I'm not much aware of this version but I am assuming I should not do production level implementation with it because may be it's not stable. (Please correct me if I am wrong)
Please suggest me a way to achieve my goal.
solidity arrays mapping solidity-best-practices solidity-design-patterns
asked 7 hours ago
Gagan
737
Goal: I wish to store an array of names with an address in a smart contract. It's more like Key-Value pairs where addresses are paired with a list of type strings.
Can I use mapping to implement this? See below for instance.
mapping(address => strings) userAddress2UserNames;
Or, there is a different approach to it?
Experiments I performed
I got no error when I compiled the above code but when I call a method which returns string from this mapping I got an error stated below.
TypeError: This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.
I'm not much aware of this version but I am assuming I should not do production level implementation with it because may be it's not stable. (Please correct me if I am wrong)
Please suggest me a way to achieve my goal.
solidity arrays mapping solidity-best-practices solidity-design-patterns
solidity arrays mapping solidity-best-practices solidity-design-patterns
asked 7 hours ago
Gagan
737
asked 7 hours ago
Gagan
737
asked 7 hours ago
Gagan
737
asked 7 hours ago
Gagan
737
asked 7 hours ago
Gagan
737
737
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago
add a comment |Â
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago
add a comment |Â
4 Answers
4
active
oldest
votes
up vote
4
down vote
How long are the user names? Maybe you can use bytes32 instead of string (each username would be limited up to 32 chars). By doing this, you wouldn't be combining two levels of dynamic arrays, which is not permitted in the current version.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
1
down vote
As it is suggested by @Patricio use bytes instead of string.
At current versions there are many limitations on string use. So better use bytes.
What you want to achieve is One to many mapping. But mapping are unique and you can't map a key with many values, so you have to use struct in this case.
Follow the below link they have explained it very well.
https://ethereum.stackexchange.com/a/38842/24373
answered 4 hours ago
Shubham Chadokar
607
add a comment |Â
up vote
1
down vote
The compiler will generate automatically getters for variables declared as public.
mapping(address => strings) userAddress2UserNames;
In this case the getter will look like
function userAddress2UserNames(address _addr, uint _index);
You have to provide an address and index to the array.
answered 1 hour ago
Ismael
13k42345
add a comment |Â
up vote
-1
down vote
given link will help you!!
follow link!!
answered 6 hours ago
Sunanda Sharma
146
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
add a comment |Â
4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
How long are the user names? Maybe you can use bytes32 instead of string (each username would be limited up to 32 chars). By doing this, you wouldn't be combining two levels of dynamic arrays, which is not permitted in the current version.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
4
down vote
How long are the user names? Maybe you can use bytes32 instead of string (each username would be limited up to 32 chars). By doing this, you wouldn't be combining two levels of dynamic arrays, which is not permitted in the current version.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
up vote
4
down vote
up vote
4
down vote
How long are the user names? Maybe you can use bytes32 instead of string (each username would be limited up to 32 chars). By doing this, you wouldn't be combining two levels of dynamic arrays, which is not permitted in the current version.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
How long are the user names? Maybe you can use bytes32 instead of string (each username would be limited up to 32 chars). By doing this, you wouldn't be combining two levels of dynamic arrays, which is not permitted in the current version.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 5 hours ago
Patricio
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 5 hours ago
Patricio
411
answered 5 hours ago
Patricio
411
411
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Patricio is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |Â
add a comment |Â
up vote
1
down vote
As it is suggested by @Patricio use bytes instead of string.
At current versions there are many limitations on string use. So better use bytes.
What you want to achieve is One to many mapping. But mapping are unique and you can't map a key with many values, so you have to use struct in this case.
Follow the below link they have explained it very well.
https://ethereum.stackexchange.com/a/38842/24373
answered 4 hours ago
Shubham Chadokar
607
add a comment |Â
up vote
1
down vote
As it is suggested by @Patricio use bytes instead of string.
At current versions there are many limitations on string use. So better use bytes.
What you want to achieve is One to many mapping. But mapping are unique and you can't map a key with many values, so you have to use struct in this case.
Follow the below link they have explained it very well.
https://ethereum.stackexchange.com/a/38842/24373
answered 4 hours ago
Shubham Chadokar
607
add a comment |Â
up vote
1
down vote
up vote
1
down vote
As it is suggested by @Patricio use bytes instead of string.
At current versions there are many limitations on string use. So better use bytes.
What you want to achieve is One to many mapping. But mapping are unique and you can't map a key with many values, so you have to use struct in this case.
Follow the below link they have explained it very well.
https://ethereum.stackexchange.com/a/38842/24373
answered 4 hours ago
Shubham Chadokar
607
As it is suggested by @Patricio use bytes instead of string.
At current versions there are many limitations on string use. So better use bytes.
What you want to achieve is One to many mapping. But mapping are unique and you can't map a key with many values, so you have to use struct in this case.
Follow the below link they have explained it very well.
https://ethereum.stackexchange.com/a/38842/24373
answered 4 hours ago
Shubham Chadokar
607
answered 4 hours ago
Shubham Chadokar
607
answered 4 hours ago
Shubham Chadokar
607
answered 4 hours ago
Shubham Chadokar
607
607
add a comment |Â
add a comment |Â
up vote
1
down vote
The compiler will generate automatically getters for variables declared as public.
mapping(address => strings) userAddress2UserNames;
In this case the getter will look like
function userAddress2UserNames(address _addr, uint _index);
You have to provide an address and index to the array.
answered 1 hour ago
Ismael
13k42345
add a comment |Â
up vote
1
down vote
The compiler will generate automatically getters for variables declared as public.
mapping(address => strings) userAddress2UserNames;
In this case the getter will look like
function userAddress2UserNames(address _addr, uint _index);
You have to provide an address and index to the array.
answered 1 hour ago
Ismael
13k42345
add a comment |Â
up vote
1
down vote
up vote
1
down vote
The compiler will generate automatically getters for variables declared as public.
mapping(address => strings) userAddress2UserNames;
In this case the getter will look like
function userAddress2UserNames(address _addr, uint _index);
You have to provide an address and index to the array.
answered 1 hour ago
Ismael
13k42345
The compiler will generate automatically getters for variables declared as public.
mapping(address => strings) userAddress2UserNames;
In this case the getter will look like
function userAddress2UserNames(address _addr, uint _index);
You have to provide an address and index to the array.
answered 1 hour ago
Ismael
13k42345
answered 1 hour ago
Ismael
13k42345
answered 1 hour ago
Ismael
13k42345
answered 1 hour ago
Ismael
13k42345
13k42345
add a comment |Â
add a comment |Â
up vote
-1
down vote
given link will help you!!
follow link!!
answered 6 hours ago
Sunanda Sharma
146
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
add a comment |Â
up vote
-1
down vote
given link will help you!!
follow link!!
answered 6 hours ago
Sunanda Sharma
146
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
add a comment |Â
up vote
-1
down vote
up vote
-1
down vote
given link will help you!!
follow link!!
answered 6 hours ago
Sunanda Sharma
146
given link will help you!!
follow link!!
answered 6 hours ago
Sunanda Sharma
146
answered 6 hours ago
Sunanda Sharma
146
answered 6 hours ago
Sunanda Sharma
146
answered 6 hours ago
Sunanda Sharma
146
146
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
add a comment |Â
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
Link only answers are not recommended, the answer will get stale if the server is down or the page has moved. It is better if you include with your answer the core of idea and use the link to expand on the details.
– Ismael
1 hour ago
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fethereum.stackexchange.com%2fquestions%2f60249%2fhow-to-map-an-address-with-a-string-array-in-solidity%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Currently you cannot use strings like that. A string itself is an array of bytes and you are mapping an array of an array of bytes. Solidity does not have the feature to do that but syntactically it is alright. Since it is a feature that is still being developed that is why you are getting that error. Which version of solidity are you using i.e what is the number beside pragma solidity?
– R.D
7 hours ago
I'm using 0.4.24
– Gagan
6 hours ago
So I really want to implement such mapping. What are the other ways of doing it? Structs? 2-d array of type bytes32? I'm quite confused.
– Gagan
6 hours ago
Try the same code in 0.4.25 or 0.5.0 then you may be able to do it. I don't know anything more sorry.
– R.D
6 hours ago