可变增量但是当我在函数中使用它时，它不会像我期望的那样处理

Question

I have a small issue with a bit of code I use to check if a browser is IE6 or IE7, I believe the problem is something simple dealing with the $browserCheck variable. My intention is to have the $browserCheck variable increment, but for testing purposes I have the variable echo as well. I thought the problem might be that the script didn't recognize where I set the variable as a integer so is used http://php.net/manual/en/language.types.type-juggling.php to change the type. The site this is on is http://www.asuperiorcallcenter.com/development/

<?php
    $browserCheck = (int) 0;
    if (strpos($_SERVER['HTTP_USER_AGENT'],'MSIE 6') !== false) { $browserCheck++; echo $browserCheck; }
    if (strpos($_SERVER['HTTP_USER_AGENT'],'MSIE 7') !== false) { $browserCheck++; echo $browserCheck; }
    function browseRight($t)
    {
        if (($t == 'css') && ($browserCheck > 0))
        {
            ?>
            <link href='http://fonts.googleapis.com/css?family=Ubuntu|Oswald' rel='stylesheet' type='text/css'>
            <style type="text/css">
            #browseRight
            {
                min-width: 1000px;
                padding: 0px 100px 0px 100px;
                height: 440px;
                background: url(browseRight/bg.jpg) repeat;
                text-align: center;
            }

            #browseRight ul
            {
                width: 1000px;
            }

            #browseRight ul li
            {
                float: left;
                list-style-type: none;
                height: 310px;
                width: 180px;
                padding: 10px 10px 10px 10px;
            }

                #browseRight ul li:hover
                {
                    background: #eee7d5;
                }

            #browseRight ul li img
            {
                height: 130px;
                clear: both;
            }

            #browseRight h2
            {
                font-family: 'Oswald', sans-serif;
                width: 100%;
                clear: both;
                font-size: 20px;
                padding: 20px 0px 0px 0px;
                color: #333333;
            }

            #browseRight ul li h2
            {
                font-family: 'Oswald', sans-serif;
                width: 100%;
                clear: both;
                font-size: 16px;
                color: #333333;
            }

            #browseRight p
            {
                font-family: 'Ubuntu', sans-serif;
                font-size: 12px;
                color: #333333;
                text-align: center;
                overflow: hidden;
            }

            #browseRight ul li p
            {
                height: 80px;
            }
            </style>
            <?php
        }
        if (($t == 'html') && ($browserCheck > 0))
        {
            ?>
                <div align="center"><div id="browseRight">
                <h2>Your Browser is out of date.</h2>
                <p>Does the website below look bad? if so it is because your browser is out of date. Fortunately you can fix this, it is as easy as updating your web browser. Below are the most popular web browsers around, visit thier websites and update to a new browser.</p>
                <div align="center"><ul>
                    <a href="http://www.google.com/chrome/" target="_blank"><li><img src="browseRight/google-chrome-logo.png"><h2>Google Chrome</h2><p>Get a fast, free web browser</p></li></a>
                    <a href="http://www.mozilla.org/en-US/" target="_blank"><li><img src="browseRight/mozilla-firefox-logo.png"><h2>Mozilla Firefox</h2><p>We are mozilla. Non-profit, for the good of the Web</p></li></a>
                    <a href="http://www.apple.com/safari/" target="_blank"><li><img src="browseRight/safari-logo.png"><h2>Safari</h2><p>Opera Software has always strived to develop the fastest and technologically most advanced browsers.</p></li></a>
                    <a href="http://www.opera.com/" target="_blank"><li><img src="browseRight/opera-logo.png"><h2>Opera</h2><p>It’s a browser. It’s a platform. It’s an open invitation to innovate. Safari sets the standard for the way browsing should be.</p></li></a>
                    <a href="http://windows.microsoft.com/en-us/internet-explorer/products/ie/home" target="_blank"><li><img src="browseRight/internet-explorer-logo.png"><h2>Internet Explorer</h2><p>A more beautiful web</p></li></a>
                </ul></div>
                </div></div>
            <?php
        }
    }
?>

Answer 1

Your problem isn't to do with $browserCheck's type, but rather its scope. It is not known inside your function. You must either use the global keyword or $GLOBALS['browserCheck'] inside the function, or better still, pass it as a parameter to the function.

However, if $browserCheck is not used anywhere else in your code, it should be defined inside the function rather than at global scope.

Best method: pass as a parameter

// Declared at global scope, unknown to the function.
$browserCheck = 0;
if (strpos($_SERVER['HTTP_USER_AGENT'],'MSIE 6') !== false) { $browserCheck++; echo $browserCheck; }
if (strpos($_SERVER['HTTP_USER_AGENT'],'MSIE 7') !== false) { $browserCheck++; echo $browserCheck; }

// Pass as a parameter to the function.
function browseRight($t, $browserCheck)
{
  // etc...
}

Alternative: access via $GLOBALS

function browseRight($t)
{
    // pull browserCheck from the $GLOBALS array
    if (($t == 'css') && ($GLOBALS['browserCheck'] > 0))
    {
    // etc...
}

Finally, you can use global $browserCheck at the top of the function, but that isn't recommended. I prefer $GLOBALS because it makes explicit in your code the fact that you're accessing a global variable.

Suggested reading: PHP's manual on variable scope.