Warning: Cannot modify header information -

[jackcoder]

Hello, 

 

I have an error on multiple pages which looks much like this. If anyone can help that would be gratefully appreciated. I would also like to ask if you may give me an explanation as to why it is occurring and not just a solution. Also when I take the second header out the error disappears.  

 

Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\blog\blog_display_post.php:47) in C:\xampp\htdocs\blog\comments.php on line 49

 

 

Here is my code:

 

if(strlen($email) > 5){

mysqli_query($con, "INSERT INTO emails (email) VALUES ('$email')");

mysqli_query($con, "INSERT INTO comments (com_name, com_com, com_date, com_blog) VALUES ('$name', '$comment', '$date', '$postid')");

 

header("Location: index.php");

}else{

mysqli_query($con, "INSERT INTO comments (com_name, com_com, com_date, com_blog) VALUES ('$name', '$comment', '$date', '$postid')");

header("Location: index.php");

}

}

}

 

[ginerjm]

You cannot send a header once ANY information of ANY kind (characters,blanks, empty lines, etc.) has been output.  The message is telling you EXACTLY what line of your code is sending something.  Stop it.

Edited August 13, 2014 by ginerjm

[CroNiX]

Also, why the duplicate code? You are doing the same insert into comments AND the same header() regardless of your strlen() check.

if(strlen($email) > 5){
  //do the insert for email
}
//do the insert for comment
//do redirect

[cyberRobot]

Out of curiosity, what's the goal behind the strlen() check? Is it just checking that $email contains a somewhat valid email address? Perhaps you're already aware of this, but PHP has a built-in function for validating email addresses:

http://php.net/manual/en/filter.examples.validation.php