pragma solidity ^0.8.0;

contract Counter {
    uint public number;
    string public name;

    constructor(string memory input_name, uint input_number){
        name = input_name;
        number = input_number;
    }

    function add () public {
        number   ;
    }

    function subtract() public {
        number --;
    }

    function update_name(string memory update) public {
        name = update;
    }

I wrote a very basic contract here and I'm wondering why I should write a return statement for each of my functions as it is already returns a value. Could someone explain my error or the point of the return statement here?

CodePudding user response：

Solidity have the "implicit return" feature, so as you noticed, you may skip the "return" statement in some cases. However, it's discourages, since you're not explicit enough and may cause a lot of confusion and issues.

For details please check the following links:

• https://medium.com/@pareshmasani/ethereum-smart-contract-implicit-return-can-go-wrong-33b41c93dbba
• https://github.com/ethereum/solidity/issues/3134
• https://blog.openzeppelin.com/instadapp-audit/