wordpress _e function

it shows"-- Debug: Undefined variable: wordscut on li开发者_如何学Pythonne 168 of /wp-content/theme"

function cutstr($string, $length) {
         $string =strip_tags($string);
        preg_match_all("/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|
[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/", $string, $info);  
         for($i=0; $i<count($info[0]); $i++) {
                $wordscut.= $info[0][$i];
                $j= ord($info[0][$i]) > 127 ? $j + 2 : $j + 1;
                 if ($j > $length - 3) {
                         return $wordscut." ...";
                 }
         }
         return join('', $info[0]);
}

the above is my function. i know in php, it's right if a variable doesn't be declared before it is used.why it shows"Undefined variable: wordscut, j..... thank you.

2,* REQUIRED: Non-printable characters were found in the '''functions.php''' file. You may want to check this file for errors.

what is Non-printable characters .how to correct it? thank you.

This is one one classic bug.

When PHP started your script, $wordscut is not defined. When you run

$wordscut .= "sometext";

The code actually do

$wordscut = $wordscut . "sometext";

At this point, $wordscut is not available, thus Undefined Variable error occurred.

To fix it, add

$wordscut = '';

before

for($i=0; $i<count($info[0]); $i++) {