Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript Vue.js Basics Sweeping Vues: Loops, Methods, Directives Getting Loopier

Posted by izzy goldman
izzy goldman
12,542 Points

Why do we have to use a Parameters in the function?

When using v-for to loop through an array of objects why do i have to add a parameter to the method to let the method know which item in the loop we are targeting? Why wont this work in the function?i.e.this.media.showDetail = !this.media.showDetail?

1 Answer

S L
S L
31,336 Points
S L
S L
31,336 Points

I had the same question for a moment,

this.media.showDetail = !this.media.showDetail would not work because "this" would reference to the "app" object and its data which has two data parameters - "title" and "mediaList". So this keyword can only be used to update "this.title" and "this.mediaList".

Since mediaList is an array of "media" objects, the "toggleDetails" method needs to know which one to update - so this is why parameter is required.