Is an element that's passed into a function a string or an object?

If I do something like getElementById() to get an anchor link then pass that variable into another function, would this be passed in as a string or an object?

I know it's a stupid question, but any help 开发者_开发百科would be appreciated.

The result of getElementById() is an object

It will be passed in as an object

An object. You will be able to access the properties of that <a> tag.

foo(document.getElementById('someID'));
function foo(element) {
    alert(element.href)
    alert(element.innerHTML);
}

getElementById returns a DOM element. When you store it in a variable or pass it into a function as a parameter its type will not change.

typeof document.getElementById("someAnchorId") // -> "object"

document.getElementById("someAnchorId").constructor // -> "HTMLAnchorElement() [...]"

Sometimes the way you treat a variable will convert it to a string unexpectedly. For example, if you append it to a string, JavaScript will automatically .toString() your object. Perhaps this behavior is what you're encountering.