Stuff I learned about Debugging on FreeCodeCamp

2 Lady bugs on a leaf

I recently got through the Debugging set of lessons on FreeCodeCamp. Here are a few points I learned.

Error Types

There are 3 types of errors:

  • Syntax – misspelled word, missing parentheses, etc.
  • Runtime – detected while running the program.
  • Semantic – detected after testing output. Program works but result is wrong. Be careful!
Short List

1. Use DevTools on Chrome or Firefox

2. Use console.log(); a lot. console.log spits out the value of whatever is in the () to the browser console, which helps you keep tabs on how a value is changing in your code. Sometimes you have to move the console.log to a different place, like before or after another function, because order matters and the value of your value can change.

3. Use console.clear(); to clear the memory of a value in the console. Sometimes it’s ok to forget.

4. Use typeof to keep track of values. For instance sometimes a number is a numeral and sometimes it’s a string. Write console.log(typeof value); and that will tell you the type for value.

5. Lastly, you have to watch out for misspellings, missing brackets or parentheses, using ‘=‘ instead of ‘==‘, or getting the dreaded infinite loop.


Next in FreeCodeCamp is Data Structures!

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