…it covers common misconceptions and bugs related to objects, prototypes, functions,
this, closures, the
argumentsobject, scoping, equality and comparisons,
instanceof, and much more. The site is very nicely written and designed, and I recommend that you check it out!
W3Fools: A W3Schools Intervention
W3Fools, a site created by “members of the front-end dev community”, explains why W3Schools is best avoided. Give it a read, and after that, you’ll know why you should generally avoid W3Schools.