Fatal error: Can't use function return value in write context

Hi Experts,

Why do I keep getting:
Fatal error: Can't use function return value in write context

...when I:
   if(isset($_POST["email"]) || !empty(trim($_POST["email"])))
   {
       $strEmail = $_POST["email"];
   }
   else 
   {
       $err = 1;
   }

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Thank you.
APD TorontoSoftware DeveloperAsked:
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GaryCommented:
if(isset($_POST["email"]) && !empty(trim($_POST["email"])))
0
APD TorontoSoftware DeveloperAuthor Commented:
makes logical sense - thanks, but same error
0
GaryCommented:
What is the whole function
0
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APD TorontoSoftware DeveloperAuthor Commented:
nothing too complex... The error is at Li.40

<?php

    $submit = '';
    $err = 0;
   
    $strName = '';
    $strEmail = '';
    $strSelect = '';
    $strMessage = '';
   
    
    if(isset($_GET["submit"]))
    {
        $submit = $_GET["submit"];
    }
 
    if($submit == '')
    {
        displayForm();
    }
    else 
    {
        validate();
    }

function validate()
{    
   global $err;
   
   global $strName;
   global $strEmail;
   global $strSelect;
   global $strMessage;
   
   if(isset($_POST["name"]))
   {
       $strName = $_POST["name"];
   }
   
   if(isset($_POST["email"]) && !empty(trim($_POST["email"])))
   {
       $strEmail = $_POST["email"];
   }
   else 
   {
       $err = 1;
   }
   
   if(isset($_POST["selection"]))
   {
       $strSelect = $_POST["selection"];
   }
   else
   { 
       $err = 1;
   }
   
   if(isset($_POST["message"]) && !empty(trim($_POST["message"])))
   {
       $strMessage = $_POST["message"];
   }
   else 
   {
       $err = 1;
   }
   
   if($err = 1)
   {
       displayForm();       
   }
   else
   {
       sendEmail();
   }    
}

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0
Ahmed MerghaniSoftware EngineerCommented:
Your code should be changed to something like this:
if(isset($_POST["email"]) && (trim($_POST["email"]) != false))
   {
       $strEmail = $_POST["email"];
   }
   else 
   {
       $err = 1;
   }

Open in new window

Prior to PHP 5.5, empty() only supports variables; anything else will result in a parse error. In other words, the following will not work: empty(trim($name)). Instead, use trim($name) == false.
See this link:
http://us3.php.net/manual/en/function.empty.php
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Ray PaseurCommented:
As a general rule, compound statements with multiple function calls in the same line of code are a path to confusion.  I believe this statement is causing the problem:

empty(trim($_POST["email"]))

Try something more like this:

$email = trim($_POST['email']);
if (empty($email)) /* DO SOMETHING */

Long ago, PHP allowed this sort of thing, but it's not allowed any more.  That's one of the risks of getting old bits of code from the internet - you don't really know if it works.  Maybe it used to work and doesn't any more.
0
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