learn-co-curriculum / js-advanced-functions-conclusion

Conclusion to the topic "JavaScript Advanced Functions"

JavaScript Advanced Functions: Conclusion

In this module, we've learned the attitude of JavaScript towards functions: it loves them!

We've seen multiple ways of defining them:

• function declarations
• function expressions
• arrow function expressions

Then we saw JavaScript pass functions around in the collection-processing methods like map, reduce, filter, etc. These lessons demonstrated that we weren't using functions and their status as first-class data to their full potential and that we could level-up our skills!

We then learned a new paradigm that embraces JavaScript's love of functions: record-oriented programming. While we started by writing functions in a way that was familiar, we learned to change our approach and pass an execution context when we called the function. We did so explicitly using call, apply, and bind. We also saw how JavaScript implictly sets context during function invocation. Lastly, we saw how the this keyword was our magic hook for grabbing the context from within a function.

Yet life with this can be tricky, so we learned how to defend against lost-context bugs and then stretched ourselves to build our own function-based framework.

We've come a long way in this module and a thorough celebration is in order. Hopefully, you've felt your mind stretch just a bit as you've come to understand JavaScript's love of functions. We hope you've come to love functions just a little bit more, too! Whatever's next in your study of JavaScript, understanding JavaScript's love of and support for using, passing, call-ing, bind-ing and using this is a crucial foundation for growing amazing JavaScript programs. Congratulations!