Gas estimation failed when using web3 provider testrpc

Question

Gas estimation failed error while invoking a simple function

pragma solidity ^0.5.9;

contract sample{
    uint number;
    function setNumber(uint _number) public{
        number = _number;
    }
    function getNumber() view public returns(uint){
        return number;
    }
}

It's deployed successfully on localhost:8545. But while checking the function from remix it gave me error.

Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending? VM Exception while processing transaction: invalid opcode

while working fine on javascript VM.

Answer 1

From solidity compiler version 0.5.5 it is compulsory to initialize contract members using constructor only so you have to initialize like this:

pragma solidity ^0.5.9;

contract sample{
    uint number;

    constructor(uint _number)public{
        number = _number;
    }


    function getNumber() view public returns(uint256){
        return number;
    }
}

If you want to go with your code then change its compiler version 0.5.9 to 0.5.4. But I recommend you to the initilize member using constructor only.