注意在PHP中通过数组进行过滤

Question

I'm creating a script that will filter out duplicate lines from a textarea. However, I am constantly getting various "Notice: Undefined offset: 2" & other higher offsets after the script has filtered through it. I'm uncertain on how to stop the messages from appearing in the results. This is what I have so far.

<?php
$textarea = $_POST['textarea'];
$split    = explode("", $textarea);
$split    = array_unique($split);
$i = 0;
if (isset($_POST['submit1'])) { 
          $submit = $_POST['submit1'];
          for ($i; $i < count($split); $i++) {
           echo $split[$i];
}
}
?>

Answer 1

Why not just foreach it?

foreach ($split as $value) echo $value;

Or you could implode it

echo implode('', $split);