A way to (poorly) generate the first 10 Fibonacci numbers using (almost) only JavaScript array functions.

fib.js

var fib = new Array(10);

for(var i = 0; i < fib.length; i++)//strangely enough, setting the values of `a` with array functions is incredibly difficult, so we'll use this instead
	fib[i] = 1;

/*^^Given Code^^*/

/*alternately, you could fill an array using the folloring code

var fib = Array.apply(null, new Array(10)).map(Number.prototype.valueOf,10);

*/

fib.forEach(function(e, i, a){//the arguments passed are e, the element, i, the index, and a, the array - this is honestly just being used as a replacement for a traditional for loop

	fib = fib.map(function(ee, ii, aa){//this is run through 10 times, as it is nested in the forEach - we update fib
		//once `i` from the outer loop is equal to `ii`, w
		if(ii < 2 || ii != i)//if it's in index 0 or 1, it already has its proper value, so we just return its current value
			//when we check if ii != i, we're checking to see if we're in the correct index, and if we're ready to update stuff
			return ee;
		return fib[ii-1] + fib[ii-2];//else, we do the standard fibonacci code
	});

})

console.log("Finished Fibonacci Below");
console.log(fib);

Alternatively you could fill the array using:

var fib = [1,1,1,1,1,1,1,1,1,1]