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!