Using the push method or .length when adding to array?

Question

What are the downsides to doing:

var myArray = [];
myArray[myArray.length] = val1;
myArray[myArray.length] = val2;

instead of:

Answer 1

I've generally thought length assignment was faster. Just found Index vs. push performance which backs that up; for my Chrome 14 browser anyway, over a single test run. However there is not much in it in Chrome.