How do you handle huge if-conditions?

Question

It\'s something that\'s bugged me in every language I\'ve used, I have an if statement but the conditional part has so many checks that I have to split it over multiple lines, u

Answer 1

    if (   (condition_A)
        && (condition_B)
        && (condition_C)
        && (condition_D)
        && (condition_E)
        && (condition_F)
       )
    {
       ...
    }

as opposed to

    if (condition_A) {
       if (condition_B) {
          if (condition_C) {
             if (condition_D) {
                if (condition_E) {
                   if (condition_F) {
                      ...
                   }
                }
             }
          }
       }
    }

and

    if (   (   (condition_A)
            && (condition_B)
           )
        || (   (condition_C)
            && (condition_D)
           )
        || (   (condition_E)
            && (condition_F)
           )
       )
    {
       do_this_same_thing();
    }

as opposed to

    if (condition_A && condition_B) {
       do_this_same_thing();
    }
    if (condition_C && (condition_D) {
       do_this_same_thing();
    }
    if (condition_E && condition_F) {
       do_this_same_thing();
    }

Most of the static analysis tools for examining code will complain if multiple conditional expressions do not use explicit parenthesis dictating expression analysis, instead of relying on operator precedence rules and fewer parenthesis.

Vertical alignment at the same indent level of open/close braces {}, open close parenthesis (), conditional expressions with parenthesis and operators on the left is an very useful practice, which greatly ENHANCES readability and clarity of the code as opposed to jamming everything that can possibly be jammed onto a single line, sans vertical alignment, spaces or parenthesis

Operator precedence rules are tricky, e.g. && has higher precedence than ||, but | has precedence than &&

So, ...

    if (expr_A & expr_B || expr_C | expr_D & expr_E || expr_E && expr_F & expr_G || expr_H {
    }

is a really easy multiple conditional expression for mere humans to read and evaluate improperly.

    if (   (  (expr_A)
            & (expr_B)
           )
        || (  (expr_C)
            | (  (expr_D)
               & (expr_E)
              )
           )
        || (   (expr_E)
            && (  (expr_F)
                & (expr_G)
               )
           )
        || (expr_H)
       )
    {
    }

There is nothing wrong with horizontal space (linefeeds), vertical alignment, or explicit parenthesis guiding expression evaluation, all of which ENHANCES readability and clarity