Iterating JavaScript Arrays

JavaScript arrays have numeric indicies, the box array has 3 properies but only two are numeric. When you use a for loop to iterate the array you will only get meow and whooo returned because they are at the numeric index 0 and 1. The reason size is not output is because it is set as a string property.

var box = [];

box['size'] = 9;
box[0] = 'meow';
box.push('whooo');

console.log(box);

for(var i = 0; i < box.length; i++) {
    console.log(box[i]);
}