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Zijun Liao
13,409 PointsSend string to browser before redirection
In this video, Alena mentioned that we should not send any string to the browser before the redirection, otherwise it causes an error.
I just wondering what does sending a string to browser means, like echo anything? I tried echo "XXX", but it still works as usual.
1 Answer

Ricardo Vermaat
150 PointsWhen you redirect using a header() function you cannot already have headers sent to the browser prior to this function.
For example:
echo 'Hello World!';
header('Location: teamtreehouse.com');
Will result in a warning:
PHP Warning: Cannot modify header information - headers already sent by (output started at / home/treehouse/workspace/index.php:2) in /home/treehouse/workspace/index.php on line 3
Here you can read more about sending headers
Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP.
Cliff Jackson
2,887 PointsCliff Jackson
2,887 PointsI am also on this part at the moment and it's a little confusing as a lot of how she explains things is very vague. One of the questions in the section after had an echo statement before the redirect which the answer was an error would be shown although the echo statement would still show.