Is this an immediately invoked function expression?

Question

I\'m a javascript newbie trying to wrap my mind around this code. I got it here http://brackets.clementng.me/post/24150213014/example-of-a-javascript-closure-settimeout-inside

Answer 1

The parantheses are optional in your example of an immediately invoked function.

(function() {
  // some code
})();

Can be re-written as

function() {
  // some code
}();

So the i in the example function's call becomes the x in the function definition.

function(x) { // x = 1
    return function() { 
        console.log(x); // x = 1
    }; 
}(1)