function - What does this JavaScript snippet mean? -

this question has answer here:

• what (function() { } )() construct in javascript? 18 answers

i have not met type of grammar before. mean? technique related?

(function(fun) {   })(myfunkyalert); 

this anonymous function run declared. parameter myfunkyalert , inside function referenced fun variable.

the reason write function avoid conflicts, due scoping.

example:

var myfunkyalert = "the funky alert";  (function(fun) {     alert(fun); })(myfunkyalert); 

this result in alert message "the funky alert".