Delete everything that has been echoed

Question

Possible Duplicate:
How to clear previously echoed items in PHP

I have this code:

<?php

$var = true;
echo 'testing';

if ($var)
{
    echo 'Hey'; //The only thing that should appear.
}
?>

How would I do to only make "Hey" appear on the site?

I don't think what you want to do is possible. As far as I know (and I could certainly be wrong), `echo` sends data back to the requester immediately. Alos, why are you echoing something if you don't want it shown to the client? — brettkelly, Jan 02 '13 at 21:15
@inkedmn Data is not pushed to the browser until the response is sent. Clever use of buffers and/or managing `STDOUT` can be used to override output via `echo` or similar functions. — phpisuber01, Jan 02 '13 at 21:17
Over complicating it just do make a word appear on his page.. — Sir, Jan 02 '13 at 21:27

score 10 · Answer 1 · answered Jan 02 '13 at 21:14

10

Without being too complicated... You can just assign your output to a variable and overwrite it.

$var = true;
$output = 'testing';

if($var)
{
    $output = 'Hey';
}

echo $output;

Alternatively, (the more complex route), you can use buffers. Research ob_start to get started learning about that.

answered Jan 02 '13 at 21:14

phpisuber01

score 5 · Accepted Answer · answered Jan 02 '13 at 21:14

5

You could use output buffering:

<?php
ob_start();
$var = true;
echo "testing";
if($var) {
    ob_clean();
    echo "Hey";
}

answered Jan 02 '13 at 21:14

2

Why is it wrong? It may be an oversimplified example, but I use `ob_clean` occasionally to "delete" output and replace it with an error message. – Niet the Dark Absol Jan 02 '13 at 21:17
2

@MattiVirkkunen Hard to tell if it's wrong if you don't know the use case. The code in the question is obviously a test. Don't punish people for answering questions. Downvote or close-vote the question instead, or give an answer that *you* think is right. – GolezTrol Jan 02 '13 at 21:17
2

It's not our job to determine if it's right or wrong. Unless it's a severe security problem like `eval` or SQL injections, it's just not our business. – Niet the Dark Absol Jan 02 '13 at 21:18
Something like this I was wanted. Thanks. And yes the code is simplified. It is an error message that will be shown. – Chengy Jan 02 '13 at 21:23
Nothing wrong with this answer. Gave the OP exactly what he wanted – Ascherer Jan 02 '13 at 21:34

Allan Spreys · Answer 3 · 2013-01-02T21:15:39.183

4

You can't, as it has been printed already.

Here is an alternative solution

<?php
   $var = true;
   if($var)
       echo "Hey";
   else
       echo "testing"
?>

edited Jan 02 '13 at 21:15

answered Jan 02 '13 at 21:15

Allan Spreys

3 Answers3