What does (function($) {})(jQuery); mean?

Question

I am just starting out with writing jQuery plugins. I wrote three small plugins but I have been simply copying the line into all my plugins without actually knowing what it

Answer 1

Actually, this example helped me to understand what does (function($) {})(jQuery); mean.

Consider this:

// Clousure declaration (aka anonymous function)
var f = function(x) { return x*x; };
// And use of it
console.log( f(2) ); // Gives: 4

// An inline version (immediately invoked)
console.log( (function(x) { return x*x; })(2) ); // Gives: 4

And now consider this:

• jQuery is a variable holding jQuery object.
• $ is a variable name like any other (a, $b, a$b etc.) and it doesn't have any special meaning like in PHP.

Knowing that we can take another look at our example:

var $f = function($) { return $*$; };
var jQuery = 2;
console.log( $f(jQuery) ); // Gives: 4

// An inline version (immediately invoked)
console.log( (function($) { return $*$; })(jQuery) ); // Gives: 4