- Naming of files/funcs/variables is important
- Magical numbers or strinags
- Nesting of the code, more than 2
- Too much if/else statements
- Duplicates of the code
- Variable that is used only once
- For/while and other loops, use arrays methods
- Redundant iteration throught arrays or objects - speed
- Take attention to the memory usage, don't create new array if it is not needed
- Divide your code into logical blocks
- BIG code blocks (inside {} - if, loop or array methods)
- Every line of code should be easy to read
- Every piece of code must be tested