JavaScript IIFE (Immediately Invoked Function Expressions)

A brief explanation about Immediately Invoked Function Expressions (IIFE). The video also discusses the difference between function declarations and function expressions and a limited explanation of how you could use an IIFE.

[naugustus]

7 year old video and still one of the easiest to understand. thank you

[rotrose]

You are GREAT. My whole GW holidays, possibly the rest of my life, is featured by your JS tutorials.

[osamagamal]

straight to the point. man I freaking love this channel.

[korhad]

Great explanation, simple and useful!

[antoniomartinez]

thank you! I think I finally understand it!

[dumchik]

> function fun1(){return "hello"}()
Uncaught SyntaxError: Unexpected token ')'
> function fun2(x){return x*x}(5)
5
> 0, function fun3(x){return x*x}(5)
25

As expected in first case I get error as I didn't use paranthesis. But how the second case and third case get executed?

[artrahman]

Thanks for explaining the hoops javascripters jump through to simulate namespaces. Doh... :)

[romeojoseph]

is a function inside of a map method a IIFE function cauz it enclosed by the parentheses tho

[jasbindarsingh]

hi Steve,
why would someone use IIFE? why do I write a function that only can be run once, isn't it contradicting the factor of reusability of a function. Can you state any use case for IIFE?

[jkk]

great tutorial;)
you put strings in the keys inside key value pair. How is it different from not putting the strings? it still works without strings.

[UlyssesAlexandreAlves]

Very low audio. Sounds like you are whispering.

[fahemzoldyck]

sound is too low, I can barely hear you !