Ethereum solidity learning record (1) the use of remix compiler

1. Browser input  Remix - Ethereum IDE

2. Compile interface: 

        

3. Running interface:

 

        

2. Code: pragma solidity ^0.4.0; indicates upward compatibility and cannot be compiled by compilers lower than version 0.4.0.

3. contract means to declare a new contract. The specific form is as follows:

contract HelloWorld{
    //此处增加代码
}

4. When updating the state of the contract, you need to pay gas, that is, the fuel fee. Operations that do not change the state of the contract do not consume gas.

        Fuel cost:

        Does not consume fuel costs: