JavaScript - invocation looks funny

Question

I'm new to JavaScript and so I've been reading a book called Speaking JavaScript. The code below shows how to create a new environment for each function so that the values in each function are isolated. I get the gist of function f() but the last line that invokes function f() is what I don't understand and the author doesn't explain it.

function f() {

    var result = [];

    for (var i=0; i<3; i++) {

        (function () {  // IIFE
            var pos = i;  // Maka a copy of i
            var func = function () {
                return pos;
            };
            result.push(func);
        }());
    }
    return result;
}

// Returns 1. I don't understand the reason behind having [1]() after f(). 
// The syntax looks funny.
console.log(f()[1]()); 

Thanks in advance.

Answer 1

To break that last line up:

f() - call the f function. This returns an array, each array element is a function itself.

[1] - access the second element of the resulting array. Arrays are zero based, so index 0 is first, 1 is second. Square brackets are used to access array elements or object properties.

() - immediately call the function of the array element we just accessed.