In Javascript, this is confusing

Every day at AcademicWorks, the Engineering Team has a Dev Sync where we share something we learned from the day before. Often times we'll hear about some new movie, a cool Kickstarter project, or an interesting ruby gem. Here is what I learned yesterday...

this is a special variable in Javascript because its available everywhere.

It can be used in:

• functions
• outside functions (in the top-level scope)
• in a string passed to eval()

What I learned

One of the benefits to using strict mode in javascript is that if you make a mistake using this, strict mode assigns this to undefined instead of the global object (window in the browser).

Example pitfall

• If you forget the keyword new when invoking a constructor function, this could be assigned to the global object if you were in "sloppy mode".

More reading:

• JavaScript’s “this”: how it works, where it can trip you up