Examples of differences between jquery neutron elements and descendant Elements

Learn jQuery selector today:

JQuery selectors include basic selectors, hierarchical selectors, filter selectors, and form selectors.

Basic selector: id, class, label name, *, element combination (div, span, p. myClass)

Level selector:

Difficulty: differences between jquery neutron elements and descendant Elements
The descendant, that is, all descendants of the current element, are counted,
Child element, which is a subset of the current element, is not counted if you go down.

For detailed analysis, refer:
Copy codeThe Code is as follows:
<Div> This is <strong> very </strong> important. </div>
<Div> This is <em> really <strong> very </strong> </em> important. </div>

The above is html. After running it, you can see it in the browser.

This is very important.
This is really very important.

To make it easy to see the effect, try adding css colors.

If you run $ ("div strong" ).css ("color", "red"), the child element strong of the div is changed to red. After running is

This is very important.
This is really very important.

If you run $ ("div> strong" ).css ("color", "blue"), the child element strong of the div is changed to blue. After running is

This is very important.
This is really very important.

It can be understood in a plain way. For example, if a family has three generations in the same hall, grandpa, father, and you, the child element of Grandpa is your father. At the same time, your father is also a descendant element of Grandpa, you are just a descendant of Grandpa.