Object Array Method

Let's take a short look.Code:
VaR o = {}
Array. Prototype. Push. Call (O, 10 );
/* Note: It must be array. Prototype rather than array, Because push is the method of the array object, not the method of the Array Function */
Alert (O. Length + "-" + O [0]);
It runs normally on Firefox. The result is alert "1-10", but the output on IE is undefined-undefined.
Why?
It turns out that in IE, it is necessary to add a Length attribute to the O object, so that IE will process your own this object like an array. Therefore, the definition of O should be changed:
VaR o = {length: 0 }.
Run again. This time, ie shows that the result is correct.
No wonder there must be a definition of the Length attribute in the jquery object definition.