pegastep Posted December 4, 2012 Share Posted December 4, 2012 Excuse my unintelligence, I'm fairly new to php, but I'm working on writing a page for a class and I'm having trouble getting it to work. Taking out all the unnecessary text, here's my code: <?php if(!isset($show)) { $show=""; } ?> <html><head><title>Lab</title></head> <body> <table> <tr><td> <h3>Menu</h3> <ul> <li><a href="lab.php?show=reagan">Ronald Reagan</a></li> <li><a href="lab.php?show=kennedy">John F. Kennedy</a></li> <li><a href="lab.php?show=roosevelt">Franklin Roosevelt</a></li> <li><a href="lab.php?show=lincoln">Abraham Lincoln</a></li></ul> </td><td class="content"> <?php if ("reagan"== $show) { echo "<h3 class=\"topHeading\">Ronald Reagan</h3><br />"; echo "<img src=\"reagan.gif\" align=\"left\" /><p>Text1</p>"; } else if ("kennedy" == $show) { echo "<h3 class=\"topHeading\">John F. Kennedy</h3><br />"; echo "<img src=\"kennedy.gif\" align=\"left\" /><p>Text2</p>"; } else if ("roosevelt" == $show) { echo "<h3 class=\"topHeading\">Franklin Roosevelt</h3><br />"; echo "<img src=\"roosevelt.gif\" align=\"left\" /><p>Text3</p>"; } else if ("lincoln" == $show) { echo "<h3 class=\"topHeading\">Abraham Lincoln</h3><br />"; echo "<img src=\"lincoln.gif\" align=\"left\" /><p>Text4</p>"; } else { echo "<center><h1>Presidential Quotes</h1><br /><h3>Text5</h3> ?> </td></tr> </table> </body> </html> The way this is supposed to operate is that the page displays "Text5" until one of the links is clicked. The link should assign a value to $show, and then the content cell will display Text1, Text2, Text3, or Text4, depending on which link was clicked. The only problem is, the content cell still shows "Text5," regardless of which links I click. I suspect this is a problem with passing the values via the link, but it could very well be something else that I'm missing. I've gone through this and I can't seem to find the problem. Does anybody see any particualrily noticable errors? Thank you for taking the time to read this. Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/ Share on other sites More sharing options...
kicken Posted December 4, 2012 Share Posted December 4, 2012 You need to use $_GET['show'] to access the variable from the URL. Being able to use $show directly is an old "feature" called register_globals which has since been removed as it generally causes more harm than good. Check out the manual page on superglobals for some details about what variables to use and when. Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397580 Share on other sites More sharing options...
us2rn4m2 Posted December 4, 2012 Share Posted December 4, 2012 All I want to say switch($_GET['show']) { case 'reagan': code ..... } Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397594 Share on other sites More sharing options...
PFMaBiSmAd Posted December 4, 2012 Share Posted December 4, 2012 This has nothing to do with your assignment (and you probably shouldn't turn in code that works like this), but when you operate on a set of related data values, you should not write out repetitious code that only differs in the values each section contains. You should use a data structure of some kind (array, database table) - <?php $data['regan'] = array('title'=>'Ronald Reagan','image'=>'reagan.gif','content'=>'Text1'); $data['kennedy'] = array('title'=>'John F. Kennedy','image'=>'kennedy.gif','content'=>'Text2'); $data['roosevelt'] = array('title'=>'Franklin Roosevelt','image'=>'roosevelt.gif','content'=>'Text3'); $data['lincoln'] = array('title'=>'Abraham Lincoln','image'=>'lincoln.gif','content'=>'Text4'); ?> <html><head><title>Lab</title></head> <body> <table> <tr><td> <h3>Menu</h3> <ul> <?php foreach($data as $key=>$arr){ echo "<li><a href='lab.php?show=$key'>{$arr['title']}</a></li>"; } ?> </ul> </td><td class="content"> <?php $show = isset($_GET['show']) ? strtolower(trim($_GET['show'])) : ''; if(isset($data[$show])){ // show exists echo "<h3 class=\"topHeading\">{$data[$show]['title']}</h3><br />"; echo "<img src=\"{$data[$show]['image']}\" align=\"left\" /><p>{$data[$show]['content']}</p>"; } else { // default echo "<center><h1>Presidential Quotes</h1><br /><h3>Text5</h3>"; } ?> </td></tr> </table> </body> </html> Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397614 Share on other sites More sharing options...
pegastep Posted December 5, 2012 Author Share Posted December 5, 2012 All I want to say switch($_GET['show']) { case 'reagan': code ..... } I tried it and that worked, thank you. However, I'd still like to be able to get to the bottom of why the if/else isn't working. You need to use $_GET['show'] to access the variable from the URL. Being able to use $show directly is an old "feature" called register_globals which has since been removed as it generally causes more harm than good. Check out the manual page on superglobals for some details about what variables to use and when. So I'd type something like if ("reagan" == $_GET['show']) ? Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397721 Share on other sites More sharing options...
pegastep Posted December 5, 2012 Author Share Posted December 5, 2012 I tried it and that worked, thank you. However, I'd still like to be able to get to the bottom of why the if/else isn't working. So I'd type something like if ("reagan" == $_GET['show']) ? Using the code I typed up there, the page will work if I go right to lab.php?show=reagan or any of the other values. However, if I just go to lab.php, I get an "Unidentified Index: show" error on all of the lines where I used the $_GET['show']. Is there any way I can fix this? Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397733 Share on other sites More sharing options...
PFMaBiSmAd Posted December 5, 2012 Share Posted December 5, 2012 (edited) Yes. See the following line from my post above - $show = isset($_GET['show']) ? strtolower(trim($_GET['show'])) : ''; This tests if $_GET['show'] is set and does some filtering/conditioning of the value and assigns the result to $show. Edited December 5, 2012 by PFMaBiSmAd Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1397735 Share on other sites More sharing options...
us2rn4m2 Posted December 11, 2012 Share Posted December 11, 2012 You can do something like this <html> <head><title>Lab</title></head> <body> <table> <tr><td> <h3>Menu</h3> <ul> <li><a href="lab.php?show=reagan">Ronald Reagan</a></li> <li><a href="lab.php?show=kennedy">John F. Kennedy</a></li> <li><a href="lab.php?show=roosevelt">Franklin Roosevelt</a></li> <li><a href="lab.php?show=lincoln">Abraham Lincoln</a></li></ul> </td><td class="content"> <?php $default = "<center><h1>Presidential Quotes</h1><br /><h3>Text5</h3>"; if(isset($_GET['show']) && !empty($_GET['show'])) { $president = null; switch($_GET['show']) { case 'reagan': $president = "Ronald Reagan"; $text = "Text1"; break; case 'kennedy': $president = "John F. Kennedy"; $text = "Text2"; break; case 'roosevelt': $president = "Franklin Roosevelt"; $text = "Text3"; break; case 'lincoln': $president = "Abraham Lincoln"; $text = "Text4"; break; default: echo $default; // or whatever you want break; } if(isset($president)) { echo '<h3 class="topHeading">' . $president . '</h3><br />'; echo '<img src="' . $president . '.gif align="left" /><p>' . $text . '</p>'; } } else { echo $default; } ?> </td></tr> </table> </body> </html> or like PFMaBISmAD, but with a little difference <?php $data['Reagan'] = array('surname' => 'Ronald ', 'content' => 'Text1'); $data['Kennedy'] = array('surname' => 'John F. ', 'content' => 'Text2'); $data['Roosevelt'] = array('surname' => 'Franklin ', 'content' => 'Text3'); $data['Lincoln'] = array('surname' => 'Abraham ', 'content' => 'Text4'); $show = (isset($_GET['show'])) ? trim($_GET['show']) : ''; $htmlTag = ''; ?> <html> <head> <title>Lab</title> </head> <body> <table> <tr> <td> <h3>Menu</h3> <ul> <?php foreach($data as $k => $v){ echo "<li><a href='index.php?show=$k'>{$v['surname']}{$k}</a></li>"; if($show == $k) { $htmlTag = "<h3 class=\"topHeading\">{$v['surname']}{$k}</h3><br />"; $htmlTag.= "<img src=\"{$k}.gif\" align=\"left\" /><p>{$v['content']}</p>"; } } ?> </ul> </td> <td class="content"> <?php echo (empty($htmlTag)) ? "<center><h1>Presidential Quotes</h1><br /><h3>Text5</h3>" : $htmlTag; ?> </td> </tr> </table> </body> </html> Quote Link to comment https://forums.phpfreaks.com/topic/271611-problem-with-code-suspecting-its-an-issue-with-passing-values/#findComment-1398785 Share on other sites More sharing options...
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