about what you see in the review element:: Before with:: After

The two tags that are seen in the review element indicate that the content is not in the element, but in the CSS, and you can see the style in the specific content.

In general, this is done in order to clear the floating (clearfix) code, preventing the clutter of the container behind it because of the floating layout.

Added before and after the elements that are selected.

The following wording:

{  content: "\0020";   Display: block;   height: 0;   Overflow: hidden;   font-size: 0;   line-height: 0;   Visibility: hidden;}

{  clear: both;}

Display has a table property.

Another: input type=checkbox element, checked= "checked" This property is added only when the page is loaded, dynamic tick does not make this attribute added, do not use the property selector to determine whether to check, using pseudo-class selector can be well judged: Checked

The Checked property specifies that the input element should be preselected when the page is loaded.

The Checked property is used with <input type= "checkbox" > or <input type= "Radio" >.

The Checked property can also be set through JavaScript code after the page is loaded.

And this checked as long as the value is checked, so if the use of the property selector, try to avoid [checked= "checked"] this, you can use [checked] to determine the existence of this property

about what you see in the review element:: Before with:: After