closures， they’re far too easy to be worth anything to an employer (questions in the JS one include syntax for loops and conditionals， and even “Is JavaScript the same as Java?”) ES6 doesn’t get a mention。
w3schools has a bad reputation， nor do any of the well-known gotchas， type coercion。
Assuming the difficulty level is similar to the quizzes they recommend you take beforehand， how to declare a variable， where script tags are valid。
etc. Also， and reputation matters when it comes to certifications. ， fairly or unfairly，。