學習遇到有關問題了，請過來人給予指點

學習遇到問題了，請過來人給予指點
當看架構源碼時(例:ci)
遇到其中不懂的寫法身邊又沒有牛人指點該怎麼辦？
就如下邊這段代碼:當strtolower($charset) != 'utf-8'時是一種處理，非而是另一種處理為什麼那？像這樣的問題如果到論壇裡去諮詢別人可能要等半天才能解決，如果搜尋尋找的話像這樣的問題又沒法下手。苦惱中..... 我該怎麼辦呢? 希望大家給予指點筆人感激不盡。

PHP code

    public function entity_decode($str, $charset='UTF-8')    {        if (stristr($str, '&') === FALSE) return $str;        // The reason we are not using html_entity_decode() by itself is because        // while it is not technically correct to leave out the semicolon        // at the end of an entity most browsers will still interpret the entity        // correctly.  html_entity_decode() does not convert entities without        // semicolons, so we are left with our own little solution here. Bummer.        if (function_exists('html_entity_decode') &&            (strtolower($charset) != 'utf-8'))        {            $str = html_entity_decode($str, ENT_COMPAT, $charset);            $str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str);            return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str);        }        // Numeric Entities        $str = preg_replace('~&#x(0*[0-9a-f]{2,5});{0,1}~ei', 'chr(hexdec("\\1"))', $str);        $str = preg_replace('~&#([0-9]{2,4});{0,1}~e', 'chr(\\1)', $str);        // Literal Entities - Slightly slow so we do another check        if (stristr($str, '&') === FALSE)        {            $str = strtr($str, array_flip(get_html_translation_table(HTML_ENTITIES)));        }        return $str;    }

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。。。我也不怎麼懂。幫你刷上去看看。
------解決方案--------------------
ok,首先,它這個函數是有缺陷的,

試一下:
echo entity_decode('叶','utf-8');
echo "\n";
echo html_entity_decode('叶',ENT_COMPAT,'utf-8');

叶 是 "葉"字.

所以,我覺得他把
&& (strtolower($charset) != 'utf-8')
這部分從條件裡拿掉更好一點,換句話說,能用html_entity_decode就先用,然後再處理無分號結尾的.

因為你只問了這個utf8的問題,相信你別的部分都沒啥問題,我也就不多嘴了.

看別人的代碼,可以細看,也可以粗看,
比如這個函數,如果你更關心其它地方,只要知道它是html_entity_decode一個變形版就行.





------解決方案--------------------
addslashes(）
------解決方案--------------------
注釋一下了：


public function entity_decode($str, $charset='UTF-8')
{
if (stristr($str, '&') === FALSE) return $str; // 如果沒能&，直接返回

// The reason we are not using html_entity_decode() by itself is because
// while it is not technically correct to leave out the semicolon
// at the end of an entity most browsers will still interpret the entity
// correctly. html_entity_decode() does not convert entities without
// semicolons, so we are left with our own little solution here. Bummer.
// 為什麼不直接用html_entity_decode() , 因為 html_entity_decode()不直接轉換不帶分號的實體。

if (function_exists('html_entity_decode') &&
(strtolower($charset) != 'utf-8'))
{

// 如果不是utf8;

$str = html_entity_decode($str, ENT_COMPAT, $charset); //根據編碼解碼
$str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str); //替換
return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str); //替換返回


}
// 如果是utf8；
// Numeric Entities 如果有數字實體則替換
$str = preg_replace('~&#x(0*[0-9a-f]{2,5});{0,1}~ei', 'chr(hexdec("\\1"))', $str);
$str = preg_replace('~&#([0-9]{2,4});{0,1}~e', 'chr(\\1)', $str);

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