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Other References

CSSStyleDeclaration JS Conversion


Elemento HTML DOM classList

❮ Objeto do Elemento

Exemplo

Adicione uma classe "myStyle" a um elemento:

element.classList.add("myStyle");

Remova a classe "myStyle" de um elemento:

element.classList.remove("myStyle");

Alterne entre duas classes para um elemento:

element.classList.toggle("newStyle");

Mais exemplos abaixo.


Definição e uso

A classListpropriedade retorna os nomes de classe CSS de um elemento.

A classListpropriedade retorna um objeto DOMTokenList.

A classListpropriedade é somente leitura, mas você pode usar os métodos add() e remove() para adicionar ou remover classes CSS.

Observação

A classListpropriedade é útil tanto para adicionar, remover e alternar classes CSS em um elemento.

Veja também:

A propriedade do elemento className

O método document getElementsByClassName()

O objeto de estilo HTML DOM


Sintaxe

element.classList

Valores de propriedade

Value Description
length The number of classes in the list.
This property is read-only.

Métodos

Method Description
add(class1,
class2, ...
)
Adds one or more classes.
contains(class) Returns true if an element has the class, otherwise false.
item(index) Returns the class name with a specified index.
Index starts at 0.
Returns null if the index is out of range.
remove(class1, class2, ...) Removes one or more classes from an element.

Removing a class that does not exist, does NOT throw an error.
toggle(class, true|false) Toggles between a class for an element.

It removes the class and returns false.
If the class does not exist, it adds the class and returns true.

The optional second parameter is a boolean that forces the class to be added or removed, regardless of whether or not it already exists.

The second parameter is not supported in Internet Explorer 11 or earlier.

Valor de retorno

Type Description
ObjectA DOMTokenList.
A list of the class names of an element.


Mais exemplos

Adicione várias classes ao elemento an:

element.classList.add("myStyle", "anotherClass", "thirdClass");

Remova várias classes de um elemento:

element.classList.remove("myStyle", "anotherClass", "thirdClass");

Quantos nomes de classe o elemento tem:

let numb = element.classList.length;

Obtenha os nomes das classes do elemento "myDIV":

<div id="myDIV" class="myStyle anotherClass thirdClass">
<p>I am myDIV.</p>
</div>

const list = document.getElementById("myDIV").classList;

Obtenha a primeira classe de um elemento:

let className = element.classList.item(0);

Um elemento an tem uma classe "myStyle"?

let x = element.classList.contains("myStyle");

Remova "anotherClass" se um elemento tiver uma classe "myStyle".

if (element.classList.contains("mystyle")) {
  element.classList.remove("anotherClass");
}

Alterne entre as classes para criar um botão suspenso:

document.getElementById("myBtn").onclick = function() {myFunction()};

function myFunction() {
  document.getElementById("myDropdown").classList.toggle("show");
}

Crie uma barra de navegação fixa:

// Get the navbar
var navbar = document.getElementById("navbar");

// Get the offset position of the navbar
var sticky = navbar.offsetTop;

// Add the sticky class to the navbar when you reach its scroll position. Remove the sticky class when you leave the scroll position.
function myFunction() {
  if (window.pageYOffset  >= sticky) {
    navbar.classList.add("sticky")
  } else {
    navbar.classList.remove("sticky");
  }
}

Páginas relacionadas

Tutorial CSS: Sintaxe CSS

Referência CSS: seletor CSS .class


Suporte ao navegador

element.classList é suportado em todos os navegadores:

Chrome IE Edge Firefox Safari Opera
Yes 10-11 Yes Yes Yes Yes

❮ O Objeto Elemento