solidity智能合约[4]-pure与view剖析

pragma solidity ^0.4.23;
contract HelloWorld{
    string public name = "jonson";

    function getName() public view returns(string){
        return name;
    }

    function changeName(string _name) public{
        name = _name;

    }

    function testPure(uint a,uint b) public pure returns(uint){
        return a+b;


    }
}