Linked Questions

7
votes
4answers
4k views

Why do we need to specify constant in the return value [duplicate]

Referring to the constant below: function totalSupply() constant returns (uint256 totalSupply);
3
votes
2answers
827 views

return function value instead of transaction receipt with web3 [duplicate]

Currently I am getting the transaction receipt instead of return value from a contract function using web3. Is there anyway to get the actual return value from a contract function call using web3 ...
1
vote
1answer
698 views

Function does not return value [duplicate]

The function caller() below does not return any value pragma solidity ^0.4.18; contract M2M{ function setvalues(uint a ,uint b) returns (uint){ return a; } function caller() ...
1
vote
1answer
575 views

Calculator Smart Contract [duplicate]

Below is my smart contract code for calculator. pragma solidity 0.4.24; contract Calculator{ uint result=10; function Calculator() public { } function getResult() public view ...
0
votes
1answer
436 views

Truffle not returning address [duplicate]

I'm trying to return sender address and value in truffle under private blockchain. When function is called from truffle console I'm not getting proper msg.sender address. Contract code pragma ...
1
vote
1answer
557 views

Can Solidity smart contracts send transactions on Ethereum? [duplicate]

I am trying to figure out whether Solidity smart contracts deployed on the Ethereum main net can send transactions. In other terms, can the address of a smart contract appear as the sender of a ...
0
votes
1answer
221 views

ERC20 TestToken code returns 0 for allowance after approval [duplicate]

I have the following code in my testtoken.js and am wondering why the assertion fails with "AssertionError: allowance wasn't set to 30: expected '0' to equal 30". it("Approve an allowance of 30 ...
0
votes
1answer
118 views

Function not returning expected value [duplicate]

I have a function in my contract which normally return uint function insertPerson( bytes32 personAddress, bytes32 email, bytes32 fname, bytes32 lname) public returns(uint index) { if(...
0
votes
1answer
85 views

Can't return string when function not pure? [duplicate]

See the below contract function of which return the string (Tested in Remix.org): pragma solidity >=0.4.22 <0.6.0; contract HelloWorld { function get() pure public returns (string memory){ ...
0
votes
1answer
132 views

How do I take value from array of objects? [duplicate]

I have a problem with my code. contract Registration { address public owner; uint conceptPrice; uint conceptValue; function Registration(uint _conceptPrice) public { owner = msg.sender; ...
1
vote
1answer
77 views

Why is it impossible to get return values of state-changing calls? [duplicate]

From reading I have surmised that it is impossible to get the return value of state changing calls. Consider this example.sol: contract F { function createChildContract() public returns (address ...
0
votes
1answer
111 views

Getting hex instead of uint through mapping [duplicate]

I have a simple method where I count how many times certain address has called method of smart contract. Here is code: mapping (address => uint) countTotal; function countSends() public returns(...
0
votes
1answer
103 views

ENS Resolver Transaction [duplicate]

If I want to find out which address a name resolves to, say example.eth, does this mean I need to send a transaction to the appropriate ENS contract for resolution? Does running a local node reduce ...
0
votes
0answers
73 views

Truffle Error: VM Exception while processing transaction: revert [duplicate]

Issue:Not able to return the input string(ofcourse it works in remix). Below is the contract. pragma solidity ^0.4.17; contract samplecontract { function viewuserName(string name) public ...
1
vote
1answer
35 views

Solidity, push overrides array [duplicate]

pragma solidity 0.4.24; contract ArraysExample { uint[] numbers; function addUser() public returns (uint[]) { numbers.push(random()); return numbers; } function random() ...

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