如果值为空则不显示任何内容

Question

On one file I have this code:

if (theForm.lqd_9.value == "")
{
    alert("You have forgotten to specify - Description!");
    theForm.lqd_9.focus();
    return (false);      
    <tr>
       <td class="theadingt" align="center" height="14" width="180">
             <b>Description:<span lang="en-us"><font color="#ff0000">*</font></span></b></td>
        <td class="theading" align="left" height="14" width="545">
    <textarea cols='48' rows='6' name="lqd_9"></textarea></td>
   </tr>

and on the receiving file I have this:

<?php echo $_POST["lqd_9"]; ?>

How can I make the code to not display anything if it's left empty?

Answer 1

You could use methods like isset or empty

<?php 
if(isset($_POST["lqd_9"])){
 echo $_POST["lqd_9"];
} 
?>

OR

<?php 
if(!empty($_POST["lqd_9"])){
 echo $_POST["lqd_9"];
} 
?>

update

It's better to use both as below.

<?php 
if(isset($_POST["lqd_9"]) && !empty($_POST["lqd_9"])){
 echo $_POST["lqd_9"];
} 
?>

PHP isset() vs empty() vs is_null()