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

Question

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.

Answer 1

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.

Answer 2

Did you try to add the

view

modifier like so ? (also it's better if you do something of your string ;) :

pragma solidity ^0.4.17;

contract Test {

    function getValue(string something) public view returns (string, uint) {
        return (something, 123);
    }
}

works like a charm on remix.

Answer 3

It might be because web3 sends transactions to methods that do not have the view or the constant modifier, instead of making a call.