is there a difference between prefix and postfix increment in solidity?

Question

I am using a simple solidity code:

pragma solidity ^0.6.0;


contract Counter {
uint public count = 1;

function incrementCount() public {
    ++count; // one way to do this
    count++; //another way to do this
}

}

since solidity is inspired by C, I am wondering if there is any difference between prefix and postfix increment.

Answer 1

Like in other programming languages, in Solidity the prefix/postfix operator means that the place of the ++ or -- determines what will happen next.

From the docs:

a++ and a-- are equivalent to a += 1 / a -= 1 but the expression itself still has the previous value of a. In contrast, --a and ++a have the same effect on a but return the value after the change.

Example:

pragma solidity ^0.8.4;

contract Counter {
 
    uint public count = 1;

    function incrementPrefixCount() public returns (uint) {
        return (++count); // returns 2
    }
    
    function incrementPostfixCount() public returns (uint) {
        return (count++); // returns 1
    }
}