Should I be using only classes for the css styles? [closed] - css

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I read an article where it was recommended that we should ONLY use classes in our markup and only use ids when we need to refere to it from javascript (as it is easier to attach functions to ids)
At the moment I only use classes when I have more than one element that needs the similar style. However the article (which I THINK I read - but have no reference) stated that we should use classes throughout
I would do this:
<header id="banner"></header>
Where as the recommendation was :
<header class="banner"></header>
(even though the banner is only used once per page)
is this the new "good practice"?
Thanks

Answer 1

As far as I know you are correct, you should use classes when you need to style multiple elements and IDs when you are only styling a unique element.

Answer 2

I think you may have stumbled on an article about object oriented css. The basic idea is that you should think of the style as a sort of abstraction which is linked to your markup via classes. I find it to be a good technique for keeping things organized, but, as with all techniques, it's not a universal hard and fast rule. I see no problem with linking style to markup with ID's, as long as that makes the most sense.
It's what "makes sense" that is the real tricky thing to define.

Answer 3

ID Attribute, Definition and Usage
The id attribute specifies a unique id for an HTML element (the value must be unique within the HTML document).
The id attribute is most used to point to a style in a style sheet, and by JavaScript (via the HTML DOM) to manipulate the element with the specific id.
Read more about it here!
CLASS Attribute, Definition and Usage
The class attribute specifies one or more classnames for an element.
The class attribute is mostly used to point to a class in a style sheet. However, it can also be used by a JavaScript (via the HTML DOM) to make changes to HTML elements with a specified class.
Read more about it here!
So, you can style using either Id's your Class's, just knowing that the class can be re-utilized on other elements across your web page, the Id must always be unique.
The reason to tell that Class's are the best attribute to utilize to apply CSS is because you can have generic class names and use then a lot through your web page, thus simplifying and reducing the time spend coding :)
Simple example:
HTML
<div id="theUniqueID">
Hello!
</div>
<div id="theUniqueIDTwo">
Hello Again!
</div>
CSS
#theUniqueID {
font-size: 15px;
text-align: right;
}
#theUniqueIDTwo {
font-size: 15px;
text-align: right;
}
Can be reduced to:
#theUniqueID, #theUniqueIDTwo {
font-size: 15px;
text-align: right;
}
And can be generically utilized across the document like this:
.format_01 {
font-size: 15px;
text-align: right;
}
Having then the HTML like:
<div class="format_01">
Hello!
</div>
<div class="format_01">
Hello Again!
</div>
<div class="format_01">
Hello Again and Again!
</div>
Ps:
Sorry for the overkill answer, but this allows others with less knowledge to learn as well.

Answer 4

Basically you should use id for unique elements that means if you want to keep an element on the page that won't be appear on the page twice then you should use id and to style a group of elements with same style or to keep some elements in the same group you should use class.
But remember, you can also use class for a single a element but you can never use an id for more than one element on the page.
For example, getElementById or $('#idOfElement') (using jQuery) returns a single element but getElementsByClassName or $('.idOfElement') (using jQuery) returns an array of matched elements. So if you have more than one element on the page using same id then you'll get only the first element that have the id, so never use id for more than one element.