如果变量大于零，如何显示/隐藏HTML块代码到PHP

    <?php
    if($_POST["ddList1"] > 0){ ?>
    <table>
        <tr>
            <td><?php echo $_POST["ddList1"]; ?></td>
            <td><?php echo $_POST["ddList1name"]; ?></td>
            <td><?php echo $_POST["ddList1desc"]; ?></td>
            <td>
                <?php
                    switch ($_POST["ddList1"]) {
                        case "1":
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        break;
                        case "2":
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        break;
                        case "3":
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>";
                        break;
                        case "4":
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>";
                        break;
                        case "5":
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>&nbsp;";
                        echo "<button type='"button'" class='"btn btn-info ButtonOne1'" onclick='"openwindow1();'" aria-label='"Left Align'"><span class='"glyphicon glyphicon glyphicon-list-alt'" aria-hidden='"true'"></span></button>";
                        break;  
                        default:
                        echo "out of range";
                    }
                ?>
            </td>
        </tr>
    </table>
<?php } ?>

if语句将运行语句echo $_POST["ddList1"];因为它遵循这种格式。

if(expression) 
 statement; 

因为"echo $_POST["ddList1"];"是下面的语句，所以条件只适用于这条语句。

你可能想试试这个格式:

<?php 
 if(condition): 
 statement1;
 statement2;
 ...
 ?>
 <h1>HTML code here!<h1>
 <?php endif; ?> 

祝你好运!

<?php if ($_POST['ddList1']): ?>
<!--Nothing between if and endif will be executed if $_POST['ddList1'] is zero-->
    <table>
        <tr>
            <td><?php echo $_POST["ddList1"]; ?></td>
            <td><?php echo $_POST["ddList1name"]; ?></td>
            <td><?php echo $_POST["ddList1desc"]; ?></td>
            <td>
                <?php
                if ($_POST['ddList1'] > 5) {
                    echo "out of range";
                } else {
                    // It looks like all the buttons are the same, so you should 
                    // be able to simplify all the repeated code in the switch
                    $button = '<button type="button" class="btn btn-info ButtonOne1" onclick="openwindow1();" aria-label="Left Align"><span class="glyphicon glyphicon glyphicon-list-alt" aria-hidden="true"></span></button>&nbsp;';
                    // This will repeat the button HTML (ddList1) times
                    echo str_repeat($button, $_POST['ddList1']);
                }
                ?>
            </td>
        </tr>
    </table>
<?php endif; ?>