Chrome控制台日志记录-Javascript

Question

I'm wondering, why do some elements appear like an array and others like HTMLSpanElement. I've attached a picture as I'm not sure how to describe this otherwise.

The following log is made via

log(returner);
log(returner[0]);

Answer 1

Is returner a jQuery object as a result of $() ? $() will always return an array, even if there is one or zero elements inside of it. Without specifying an index in your first console.log, the entire contents of the array are outputted. In the second console.log, you include an array index, so only the element matching that index is outputted.

Answer 2

Because the element that appears like an array IS an array - it's an array of DOM element objects (HTMLSpanElement, etc).

When you log the first element of the array with returner[0] , that element is a DOM object, so it logs it as an object.

Answer 3

因为（看起来） returner不是元素，而是元素数组。