Difference between class and id in CSS.

The attributes of elements in CSS are often the subject of controversy between professionals and amateurs. Whether it is necessary to apply one or the other, how expedient it is with an identical result, which code will be less expensive and more correct, and such questions are constantly discussed, including affecting the class and id attributes.


Div class - an attribute of an element that assigns it to a class.

Div id is an attribute of an element that uniquely identifies it.


The difference between class and id in CSS is not considered cardinal, and often one or another is used depending on the author's bias. The main difference between class and id is that the first can be given to several elements, while the second is unique and is assigned to one element on the page. Using a div id avoids the multilevel nesting that comes with using a div class.

In addition, the id attribute, unlike class, can be used for anchor links, for this it is enough to give it to an element and link to this element with an anchor. Also, id will take precedence in the CSS table if it is specified at the same time as class. The latter, in turn, allows multiple classes to be applied to a single element. Class names can be written separated by spaces, the identifier does not imply such a call. Another advantage of id is the ability to search for an element in code by this attribute using the document.getElementById () function.

Conclusions TheDifference.ru

  1. Div class - assigns a class to an element, div id - identifies.
  2. Class is assigned to multiple elements, id is unique on the page.
  3. One element can be assigned multiple classes by class, and only one id.
  4. Priority in CSS remains with id.
  5. Searching in code using the id attribute is easier.