How to learn to quickly count logical expressions?

Question

Programming

As a programmer, I often come across logical expressions. As soon as you need to write something like A || B & (C || D) , I start to calculate for a long time what will happen at the output. How to learn to solve such problems as efficiently as possible?

Answer 1

Break the complex into simple parts. A || B & (C || D) come up with a more practical example (equivalent to yours).

if (!file.exist || (file.type != DIRECTORY)  & (file.creationDate < lastGoodDate || file.size > maxSize))
{
   printErrorMessage();
}

This is hard to write and read. A longer, but more understandable version:

bool isBadFile(file)
{
   if (!file.exist)
      return true; 

   if (file.type == DIRECTORY)
      return fasle; //skip directories

   bool isTooOld = file.creationDate < lastGoodDate;
   bool isTooBig = file.size > maxSize;

   return isTooBig || isTooOld
}

if (isBadFile(file))
{
   printErrorMessage();
}

Answer 2

Avoid such decisions, rewrite, write clear, transparent code, shoot those who write like a Hindu.