How to Debug
Last updated
Last updated
Table of Contents:
Debugging refers to the process of detecting, locating, and fixing problems, or “bugs,” in computer code.
It is one of the most essential skills to learn and yet, it is incredibly difficult to learn, particularly for new programmers.
One strategy that is widely used in the industry is called rubber-ducking which is essentially explaining your problem to a rubber duck.
Yes... a literal rubber duck.
How does this help you resolve the problems in your code? The idea of debugging a program by talking to a rubber duck comes from The Pragmatic Programmer (Hunt & Adams, 1999):
A very simple but particularly useful technique for finding the cause of a problem is simply to explain it to someone else. The other person should look over your shoulder at the screen, and nod his or her head constantly (like a rubber duck bobbing up and down in a bathtub). They do not need to say a word; the simple act of explaining, step by step, what the code is supposed to do often causes the problem to leap off the screen and announce itself. (p. 95)
First, grab a rubber duck (or some other inanimate object that you feel comfortable talking to).
Then, have a conversation with your duck where your duck asks you the following questions (and you reply!):
🦆 What is your code supposed to do? What should the output be?
💬 Start by telling your duck about the goal or purpose of your program.
🦆 What is your code actually doing, and how is it different from what you want it to be doing?
💬 Describe the error or incorrect output you are encountering. If you have multiple problems, pick one and come back to the others later.
🦆 Where does the code first go wrong?
💬 Describe out loud to your rubber duck what each line of your code is doing, and try to trace the problem back to its source. You may find that a simple typo is causing all of your problems!
🦆 What have you done so far to try to fix your program?
💬 Describe any approaches you have tried and how they worked or did not work.
🦆 What other ideas do you have?
💬 Get creative, and test out other possible solutions, starting with the simplest and easiest approach.
