Revision 539769 of Window.scrollY

<div>
 {{APIRef}}</div>
<h2 id="Summary" name="Summary">Summary</h2>
<p>Returns the number of pixels that the document has already been scrolled vertically.</p>
<h2 id="Syntax" name="Syntax">Syntax</h2>
<pre class="syntaxbox">
var y = window.scrollY;</pre>
<ul>
 <li><code>y</code> is the number of pixels that the document is currently scrolled from the top.</li>
</ul>
<h2 id="Example" name="Example">Example</h2>
<pre class="brush:js">
// make sure and go down to the second page 
if (window.scrollY) {
  window.scroll(0, 0);  // reset the scroll position to the top left of the document.
}

window.scrollByPages(1);</pre>
<h2 id="Notes" name="Notes">Notes</h2>
<p>Use this property to check that the document hasn't already been scrolled some if you are using relative scroll functions such as {{domxref("window.scrollBy")}}, {{domxref("window.scrollByLines")}}, or {{domxref("window.scrollByPages")}}.</p>
<p>The <code>pageYOffset</code> property is an alias for the <code>scrollY</code> property:</p>
<pre>
window.pageYOffset == window.scrollY; // always true</pre>
<p>For cross-browser compatibility, use <code>window.pageYOffset</code> instead of <code>window.scrollY</code>. <strong>Additionally</strong>, older versions of Internet Explorer (&lt; 9) do not support either property and must be worked around by checking other non-standard properties. A fully compatible example:</p>
<pre class="brush:js">
var x = (window.pageXOffset !== undefined) ? window.pageXOffset : (document.documentElement || document.body.parentNode || document.body).scrollLeft;
var y = (window.pageYOffset !== undefined) ? window.pageYOffset : (document.documentElement || document.body.parentNode || document.body).scrollTop;</pre>
<h2 id="Specification" name="Specification">Specification</h2>
<ul>
 <li>CSSOM View Module: <a href="https://dev.w3.org/csswg/cssom-view/#widl-Window-scrollY">window.scrollY</a> (Editor's Draft)</li>
</ul>
<h2 id="See_also" name="See_also">See also</h2>
<ul>
 <li>{{domxref("window.scrollX")}}</li>
</ul>