Home/ Questions/Q 8573237
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-11T19:12:15+00:00

The following code is taken from the ‘JavaScript by Example Second Edition’. I think

  • 0

The following code is taken from the ‘JavaScript by Example Second Edition’.

I think the code

if (!e) var e = window.event; // Internet Explorer

should be 

if (!e) e = window.event; // Internet Explorer

What do you think? Is it right? Or maybe the code should remains as is?

<html>
<head>
    <title>Mouse Coordinates</title>
    <script type="text/javascript">
        function getCoords(e) {
            var x = 0; // x and y positions
            var y = 0;
            if (!e) var e = window.event; // Internet Explorer
            if (e.pageX || e.pageY) { // Firefox
                x = e.pageX;
                y = e.pageY;
            }
            else if (e.clientX || e.clientY) {
                x = e.clientX + document.body.scrollLeft
              + document.documentElement.scrollLeft;
                y = e.clientY + document.body.scrollTop
                + document.documentElement.scrollTop;
            }
            // x and y contain the mouse position
            // relative to the document
            alert(x + ", " + y);
        }
    </script>
    </head>
        <body>
            <div style="background-color: aqua; position: absolute; top: 50px"
                onmouseover="return getCoords(event);">
                <h1>Mouse positions are relative to the document, not the
&lt;div&gt; container</h1>
            </div>
        </body>
</html>
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Yes, you can remove the var statement inside that function.

    Variables in functions are declared in scope in 2 ways, either via the ‘var’ keyword, or by being defined as a parameter being passed into the function.

    • 0