I have had to convert recently IDs from 15 to 18 chars length in an Excel formula using a MS Office Spanish version (formulas are different between English and Spanish MS Office versions!). This is the one I’ve used:
After taking the exam I can give you some hints. It is a very deep technical exam, meaning most of the question give you a piece of code, sometimes quite a lof of lines of code for a single question, and you have to provide the output of that piece of code. For example, expect to see an array that has a lot of manipulations with map(), reduce() and so on. So you really need hands on this. I recommend you to use codepen.io or another tool to run as many examples as you can to understand all the different concepts (scope, coercion, promises and so on), and do it lots of times until you have everything very clear. I can tell you this exam is not an easy one if you don’t have hands-on experience and you only have theorical knowledge.
Variables / Types: Format Dates (toLocaleDateString())
Arrays: Lots of questions about .map() and .reduce() functions and also slice() and splice().
Coercion: Questions about giving the output. For example: what’s the result of this sentence?: null + 10 + ‘4’ + NaN
Browser APIs: Questions on Window.localStorage and Window.history
Objects / Classes: tons of questions about scope and “this”
Events: Notice the different between button.addEventListener(“click“, handleClick); (click vs onclick)
Modules: Lots of questions about exporting and importing (named exports, vs export all)
Error handling: Give the output of the try / catch / finally flows
Debugging / Testing: few questions about how to debug. Also questions about false positives and false negatives tests (watch out the theory here)
Promises: can you put a “.then()” after a “.catch()” ?
Node.js: Quite a few questions around “npm” and its package.json. How do you add dependencies? dependencies only for dev, etc. On the CLI, study the “–inspect” argument.
Scope: Not many but still relevant, var vs let comparision
Others: know the difference between setTimeout() and setInterval()
Now, with Lightning Web Components this is quite different. We can leverage the new standards and re-use these skills everywhere, which is great to build applications outside of the Lightning Platform.
I’ll focus on the Exam Outline points and hope to have a good day to pass it! Exam Guide