In VS I am told this function “does not return a value in all control paths.” A bot told me specifically the issue is with this line: else if (letter + key <= 90). It said that if the outcome results in letter + key equally exactly 90 then a value is not returned, but I thought that was covered where ‘<=’ means ‘less than or equals.’

char rotate(char letter, int key)
{
    if (isalpha(letter) == true)
    {
        if (letter + key > 90)
        {
            int overage = letter + key - 90;
            letter = 64 + overage;

            while (letter > 90)
            {
                overage = letter - 90;
                letter += overage;
            }

            return letter;
        }

        else if (letter + key &lt;= 90)
        {
            letter += key;
            return letter;
        }
    }

    else if (isalpha(letter) == false)
    {
        return letter;
    }
  • towerful@programming.dev
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    1 year ago

    I’m a fan of early returns.
    So

    if(isalpha(letter) == false) return letter
    if(letter whatever) {
       Do thing
       Return letter
    }
    if(letter something else) {
       Do something else
       Return letter
    }
    throw error("unprocessable letter")
    

    I find it lets me mentally walk through all the paths more easily.
    And if something gets too complex for this, then I need to break it down into further functions