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Fareez Ahmed
12,728 Pointsbookmarklets as IIFEs
Hi, I came across this blog post:
http://blog.teamtreehouse.com/creating-bookmarklets-for-fun-and-profit
and I was wondering, why are a lot of bookmarklets written as IIFEs (Immediately Invoked Function Expressions). Can someone explain the logic behind this?
Thanks!
2 Answers
Dave McFarland
Treehouse TeacherIIFEs (Immediately Invoked Function Expressions) let you run code that doesn't interfere with what's called the global namespace. When you run a bookmarklet, you're executing JavaScript code on the page you are currently on -- that page may already have JavaScript programs running on it.
When you use an IIFE the variables you create are never exposed to any other JavaScript code on the page -- this means you can use variable names without worrying that you might use the same name as other code on the page. In other words, your code won't accidentally overwrite and ruin JavaScript code already running on the page.
More info here: Immediately Invoked Function Expression
Fareez Ahmed
12,728 PointsInteresting, thanks Dave McFarland! So what I'm deducing is that an IIFE is a type of closure?