In this task, would some kind people tell me, why should we use “#” before thumbnail instead of “.” ?
When should I use “#”?
#thumbnail
{
}
instead of
.thumbnail
{
}
I ussually go with the . but, some apps are more demading for the #
Also could you put a link to the challenge next time instead of a screenshot?
. is for classes, # is for id
usually you use classes to style via css, and id (which must be unique in the document) to manipulate elements with javascript
<img id="an-id" class="a-class" ... >
this img element can be selected using the class selector .a-class or the id selector #an-id
The FCC challenges tend to make you use # because it’s easier for the tests to handle. That should probably be fixed. Best practice in CSS these days is to use . (a dot) to match the class, even if there’s just one element using that class.
You’d match the id using # when you have JavaScript that can only target a single element, such as ReactDom.render