The entries() method of the DOMTokenList interface returns an iterator allowing you to go through all key/value pairs contained in this object. The values are Arrays which have [key, value] pairs, each representing a single token.

Returns an iterator.

In the following example we retrieve the list of classes set on a <span> element as a DOMTokenList using Element.classList. We when retrieve an iterator containing the key/value pairs using entries(), then iterate through each one using a for...of loop, writing them to the <span>'s Node.textContent.

First, the HTML:

<span class="a b c"></span>

Now the JavaScript:

const span = document.querySelector("span");
const classes = span.classList;
const iterator = classes.entries();

for (const value of iterator) {
  span.textContent += `(${value})`;
}

The output looks like this:

• DOMTokenList.foreach(), DOMTokenList.keys and DOMTokenList.values.