window.scrollTop is undfined

why would window.scrollTop be undefined?

https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollTop

The Element.scrollTop property gets or sets the number of pixels that
an element’s content is scrolled vertically.

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An element’s scrollTop value is a measurement of the distance from the
element’s top to its topmost visible content. When an element’s
content does not generate a vertical scrollbar, then its scrollTop
value is 0.

jQuery(window).on('scroll', function() {
        if(window.scrollTop > 0) {
            console.log('of the top')
            console.log('scroll top value is: ' + window.scrollTop)
        } else {
            console.log('the top')
            console.log('scroll top value is: ' + window.scrollTop)
        }
    })

All I’m getting in my console log is:

scroll top value is: undefined

and I’m always getting an evaluation of in the if else:

of the top

even if I’m scrolled to the top of the page.

Why would window.scrollTop be undefined?

https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollTop does window not count as an element?

>Solution :

You need to use the jQuery $ identifier as well as the parenthesis () for .scrollTop() in order to get the position

Here’s the executable code:

<script>
jQuery(window).on('scroll', function() {
        if($(window).scrollTop() > 0) {
            console.log('of the top')
            console.log('scroll top value is: ' + $(window).scrollTop())
        } else {
            console.log('the top')
            console.log('scroll top value is: ' + $(window).scrollTop())
        }
    })
</script>