Programming Tips: Don't mix 2 tasks together

In my professional life, I've seen lots of people with different coding styles, but one of the most important issues that most programmers have is due to the fact that they mix different tasks together.

Rule of 30

You've probably heard of rule of 30 in clean code, but did you ever thought why a simple rule like this is so important?
The reason is simple: To make you create simpler methods.
So if you have a method that will do 10 things together, you will be forced to write 10 different methods and then call them

Why some people avoid it

Well, in my opinion 30 lines is enough for implementing a singe task, most of the times. And I reserve 1% for something that is an exception, but what about the other times?!
In my opinion, most of the times it is hard for people decide about separating different parts of a big task to several smaller tasks so they try to solve the whole problem in a big and ugly method.

Example

Any normal method that you write in daily basis can be a simple example for this mater. For instance, reading data from some text and filling your tables in DB. Very easy, right?

If you don't divide your big task, you will have a big method for doing everything and then you probably try to read every line and for each line you will try to save data into your DB. Right?
It is ugly code and I didn't even started! :)
OK, hopefully you have a DB with good structure, so you need to put your stuff in tables that they have some items it-selves.
....And most of the times your text data is not normalized data ( you wish! :) )
So you will start to reading data, line by line. storing common data into parent tables the first time and then ignoring them next times.

You see where it is going! right?! UGLY!UGLY! LAKH!

What should you do?!

You have a task to read data from text and store in in DB right?! So read the data first into structured objects (like DTO) and then save them into DB in another method. You have complex objects?! easy! create a method for reading each one and call them inside the parent!

What is the benefits? 

* It is easy to understand what you did. So easy to maintain and debug

* You have separated methods based on your functionalities. So you can reuse your code. 

* You managed your situation on each method based on what it has to do. So your code handles the situation better