[Ethereum] Remix How Do I Get a Value Returned From A Function In Solidity

remixsolidity

How do I get a return value in solidity?

I'm using some test code in remix, but I don't understand where the output is displayed.

my code is as follows:

pragma solidity ^0.4.17;

contract Test {
    function getValue(string something) public returns (uint) {
        return 123;
    }
}

when I call the getValue method with a string "testing123" (quote marks required), I expected the function to return 123.

the properties returned on Remix are:

decoded input:

decoded output

{ "string something": "testing123" }

I have read the documentation but I may not be understanding some part of it. Any help is appreciated.

Best Answer

I did copy paste your code and it works fine (although there are some warnings!). Once you deployed the contract (with the deploy button) you can call your function with the getValue button.

You should see the result in the bottom gray box. It shouws the whole transaction and also the decoded output.

UPDATE

According to the yellow paper:

Essentially the output is used only when the message call is performed by the execution of a contract code. Otherwise, i.e. when the message call is due to a transaction (that triggers the execution) the output should be ignored, as reported.

Related Solutions

[Ethereum] how to return uint256 from solidity to javascript

I think the contract address or ABI is not correctly set in your case because I tested and it works perfectly.

Please check if correct contract address and ABI is updated in your javascript file.

[Update]

-----------------------

As you asked, I am attaching my code:

Solidity Code:

pragma solidity ^0.4.0;

contract testContract {
    uint256 num1;

    address[] contracts = [0x36eaf79c12e96a3dc6f53426c, 0xf235aa56dd96bda02acfb361e];

    function getContractsCount() constant returns (uint256) {
          return contracts.length;
    }

}

jQuery code:

$(document).ready(function(){
    function contractInvocation() {
        var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
        var abi = <ABI>;
        var testContract = web3.eth.contract(abi);
        var contractInstance = testContract.at('<Contract Address>');
        var y = contractInstance.getContractsCount.call({from:web3.eth.accounts[0]}).c[0];
        console.log(y);
});

solidity structs – Returning Structs in Solidity’s New Version

Yes we can return structs.

But only in internal function calls.

pragma solidity ^0.4.19;

contract tester{

struct Person
{
    string name;
    uint age;
}

function getSome() public returns (Person a)
{
    Person memory p;
    p.name = "kashish";
    p.age =20;
    return p;
}

function wantSome() public returns (string,uint)
{
     Person memory p2 =getSome();
     return (p2.name,p2.age); // return multiple values like this
}
}

Best Answer

Related Solutions

[Ethereum] how to return uint256 from solidity to javascript

solidity structs – Returning Structs in Solidity’s New Version

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