The HTMLCollection.length property returns the number of items in a HTMLCollection.
An integer value representing the number of items in a HTMLCollection.
The length property is often useful in DOM programming. It's often used to test the length of a list, to see if it exists at all. It's also commonly used as the iterator in a for loop, as in this example.
// All the elements with the class ".test" in the document
const items = document.getElementsByClassName("test");
// For each test item in the list,
// append the entire element as a string of HTML
let gross = "";
for (let i = 0; i < items.length; i++) {
gross += items[i].innerHTML;
}
// gross is now all the HTML for the test elements