How Web Apps Work: JavaScript and the DOM

[utterances-bot]

How Web Apps Work: JavaScript and the DOM · Mark's Dev Blog

https://blog.isquaredsoftware.com/2020/11/how-web-apps-work-javascript-dom/

[abmi108]

Fantastic resource. Thank you for putting in the effort. Just wanted to point out some of the typos I noticed here (correct me if I am wrong) since I couldn't find a corresponding repo.

• In the JS in Depth section under Objects: it should be

  Object.assign(target, src1, src2) 

  instead of

  Object.assign(target, src1, src1)

• In the JS in Depth section under Arrays: the link for array destructuring is broken as the link should be

  https://blog.isquaredsoftware.com/presentations/2019-05-js-for-java-devs/#/48 

  instead of

  https://blog.isquaredsoftware.com/persentations/2019-05-js-for-java-devs/#/48

  The error is in the mis-spellling of "presentations" as "persentations".

Apart from that amazing read. Thank You!

[markerikson]

Thanks for pointing these out!

[MarcosNASA]

Hey, Mark! Awesome content! I'm gonna start recommending this as a starting point for folks who are jumping from any language to JS. :tada:

However, there's something around scope that confused me a bit:

let and const are block-scoped - they only exist within the curly braces block where they're declared, and the same variable name can be reused and shadowed inside of nested blocks. var is function-scoped - no matter where it's used, the declaration is hoisted to act as if it was written on the first line of the function it's inside, and reusing the same name will override the earlier declaration.

Indeed, let and const "can be reused and shadowed inside of nested blocks", but also var can (when the nested blocks are functions)! Instead, it kinda sounds as if anytime you use the same name for a var-declared variable it will override any previous. Counter-example:

var x = 0
;(function() { var x = 3 })()
console.log(x)

Might just be me, though, but I think that stating that any variable declarator can shadow each other in nested scope-bounding-blocks but that, within the same scope-bounding-block, only var allows "multiple declarations" (explaining that scope-bounding-blocks means any block for const and let and only functions for var) makes the point clearer.

Anyway, thanks for your work!

[ghost]

The link to Immer is broken. Thank you for all of this by the way : )