checklist.md

1. [VARIABLES] - use variables for the main values so that you can reuse them and give them descriptive names.
2. [CODE STYLE] - Avoid reassigning variables values. It's better to use const instead of let.
3. [CODE STYLE] - You should return the value immediately in if statements. And don't use else after return statement. If return is performed - code after it won't be executed anyway. BAD EXAMPLE:

if (condition) {
  return x;
} else {
  return y;
}

GOOD EXAMPLE:

if (condition) {
  return x;
}
return y;

4. [REUSABILITY] - Give variables abstract names - it's will be easiar for another person to read your code
5. [VARIABLES] - Don't hardcode some values that may change in the future in variable names (numbers etc.)

BAD EXAMPLE:

const discountForThreeDays = 50;

GOOD EXAMPLE:

const basicDiscount = 50;