php±àÂëheaderÖвÎÊý˵Ã÷
ÍøÒ³µÄ»º´æÊÇÓÉHTTPÏûϢͷÖеġ°Cache-control¡±À´¿ØÖƵ쬳£¼ûµÄȡֵÓÐprivate¡¢no-cache¡¢max-age¡¢must-revalidateµÈ£¬Ä¬ÈÏΪprivate¡£Æä×÷Óøù¾Ý²»Í¬µÄÖØÐÂä¯ÀÀ·½Ê½·ÖΪÒÔϼ¸ÖÖÇé¿ö£º £¨1£© ´ò¿ªÐ´°¿Ú
ֵΪprivate¡¢no-cache¡¢must-revalidate£¬ÄÇô´ò¿ªÐ´°¿Ú·ÃÎÊʱ¶¼»áÖØÐ·ÃÎÊ·þÎñÆ÷¡£
¶øÈç¹ûÖ¸¶¨ÁËmax-ageÖµ£¬ÄÇôÔÚ´ËÖµÄÚµÄʱ¼äÀï¾Í²»»áÖØÐ·ÃÎÊ·þÎñÆ÷£¬ÀýÈ磺
Cache-control: max-age=5(±íʾµ±·ÃÎÊ´ËÍøÒ³ºóµÄ5ÃëÄÚÔٴηÃÎʲ»»áÈ¥·þÎñÆ÷) £¨2£© ÔÚµØÖ·À¸»Ø³µ
ֵΪprivate»òmust-revalidateÔòÖ»ÓеÚÒ»´Î·ÃÎÊʱ»á·ÃÎÊ·þÎñÆ÷£¬ÒÔºó¾Í²»ÔÙ·ÃÎÊ¡£
ֵΪno-cache£¬ÄÇôÿ´Î¶¼»á·ÃÎÊ¡£
ֵΪmax-age£¬ÔòÔÚ¹ýÆÚ֮ǰ²»»áÖØ¸´·ÃÎÊ¡£ £¨3£© °´ºóÍ˰´Å¤
ֵΪprivate¡¢must-revalidate¡¢max-age£¬Ôò²»»áÖØ·ÃÎÊ£¬
ֵΪno-cache£¬Ôòÿ´Î¶¼Öظ´·ÃÎÊ £¨4£© °´Ë¢Ð°´Å¤
ÎÞÂÛΪºÎÖµ£¬¶¼»áÖØ¸´·ÃÎÊ Cache-controlֵΪ¡°no-cache¡±Ê±£¬·ÃÎÊ´ËÒ³Ãæ²»»áÔÚInternetÁÙʱÎÄÕ¼ÐÁôÏÂÒ³Ãæ±¸·Ý¡£ ÁíÍ⣬ͨ¹ýÖ¸¶¨¡°Expires¡±ÖµÒ²»áÓ°Ïìµ½»º´æ¡£ÀýÈ磬ָ¶¨ExpiresֵΪһ¸öÔçÒѹýÈ¥µÄʱ¼ä£¬ÄÇô·ÃÎÊ´ËÍøÊ±ÈôÖØ¸´ÔÚµØÖ·À¸°´»Ø³µ£¬ÄÇôÿ´Î¶¼»áÖØ¸´·ÃÎÊ£º Expires: Fri, 31 Dec 1999 16:00:00 GMT ±ÈÈ磺½ûÖ¹Ò³ÃæÔÚIEÖлº´æ httpÏìÓ¦ÏûϢͷ²¿ÉèÖ㺠CacheControl = no-cache
Pragma=no-cache
Expires = -1 ExpiresÊǸöºÃ¶«¶«£¬Èç¹û·þÎñÆ÷ÉϵÄÍøÒ³¾³£±ä»¯£¬¾Í°ÑËüÉèÖÃΪ-1£¬±íʾÁ¢¼´¹ýÆÚ¡£Èç¹ûÒ»¸öÍøÒ³Ã¿ÌìÁ賿1µã¸üУ¬¿ÉÒÔ°ÑExpiresÉèÖÃΪµÚ¶þÌìµÄÁ賿1µã¡£ µ±HTTP1.1·þÎñÆ÷Ö¸¶¨CacheControl = no-cacheʱ£¬ä¯ÀÀÆ÷¾Í²»»á»º´æ¸ÃÍøÒ³¡£ ¾Éʽ HTTP 1.0 ·þÎñÆ÷²»ÄÜʹÓà Cache-Control ±êÌâ¡£
ËùÒÔΪÁËÏòºó¼æÈÝ HTTP 1.0 ·þÎñÆ÷£¬IEʹÓÃPragma:no-cache ±êÌâ¶Ô HTTP Ìá¹©ÌØÊâÖ§³Ö¡£
Èç¹û¿Í»§¶Ëͨ¹ý°²È«Á¬½Ó (https://)Óë·þÎñÆ÷ͨѶ£¬ÇÒ·þÎñÆ÷ÔÚÏìÓ¦Öзµ»Ø Pragma:no-cache ±êÌ⣬
Ôò Internet Explorer²»»á»º´æ´ËÏìÓ¦¡£×¢Ò⣺Pragma:no-cache ½öµ±ÔÚ°²È«Á¬½ÓÖÐʹÓÃʱ²Å·ÀÖ¹»º´æ£¬Èç¹ûÔڷǰ²È«Ò³ÖÐʹÓ㬴¦Àí·½Ê½Óë Expires:-1Ïàͬ£¬¸ÃÒ³½«±»»º´æ£¬µ«±»±ê¼ÇΪÁ¢¼´¹ýÆÚ header³£ÓÃÖ¸Áî
header·ÖΪÈý²¿·Ö£º
µÚÒ»²¿·ÖΪHTTPÐÒéµÄ°æ±¾(HTTP-Version)£»
µÚ¶þ²¿·ÖΪ״̬´úÂë(Status)£»
µÚÈý²¿·ÖΪÔÒò¶ÌÓï(Reason-Phrase)¡£ // fix 404 pages: ÓÃÕâ¸öheaderÖ¸ÁîÀ´½â¾öURLÖØÐ´²úÉúµÄ
Ïà¹ØÎĵµ£º
<?php
$txt = 'Hello world';
echo $txt;
?>
<br/>
×Ö·û´®Á¬½Ó(.)
<br/>
echo 'Hello world'. "" . '1234' Êä³ö£º
<?php
$txt1 = 'Hello world';
$txt2 = '1234';
  ......
php100ѧϰ
Ô´Â룺http://bbs.php100.com/read-htm-tid-11052.html
1¡¢PHP±¸·ÝÊý¾Ý¿âµÄÔÀí
2¡¢PHPÖÐmysqlÏà¹Øº¯Êý
mysql_list_tables() ±í²éѯº¯Êý£¬ÀàËÆmysql_query() º¯Êý
mysql_fetch_field() ×Ö¶ÎÐÅÏ¢º¯Êý£¬·µ»Ø¾ä±ú
Name ×ֶεÄÃû³Æ
Table ×Ö¶ÎËùÊôÊý¾Ý±íµÄÃû³Æ
Type ×ֶεÄÀàÐÍ
max_length ×ֶεÄ×î´ó³¤¶È
......
PHP: echo substr("1234567", 1, 3);
ºÍ PHP: echo substr(123456,1, 3);
ÊÇÒ»ÑùµÄ
¶¨Òå
Ò»°ãÓÃË«ÒýºÅ»òµ¥ÒýºÅ±êʶһ¸ö×Ö·û´®¡£±ÈÈç PHP: $str = "i love u";
$str = 'i love u';
ËüÕßÁ½ÕßÊÇÓÐÒ»Ð©Çø±ðµÄ¡£ºóÕß½«Ò»Çе¥ÒýºÅµÄÄÚÈݶ¼»áµ±×÷×Ö·û´¦Àí£»Ç°ÕßÔ ......
˵Ã÷ array preg_split ( string $pattern, string $subject [, int $limit [, int $flags]] ) ·µ»ØÒ»¸öÊý×飬°üº¬ subject ÖÐÑØ×ÅÓë pattern Æ¥ÅäµÄ±ß½çËù·Ö¸îµÄ×Ó´®¡£ Èç¹ûÖ¸¶¨ÁË limit£¬Ôò×î¶à·µ»Ø limit ¸ö×Ó´®£¬Èç¹û limit ÊÇ -1£¬ÔòÒâζ×ÅûÓÐÏÞÖÆ£¬¿ÉÒÔÓÃÀ´¼ÌÐøÖ¸¶¨¿ÉÑ¡²ÎÊý flags¡£ flags ¿ÉÒÔÊÇÏÂÁбê¼ÇµÄÈÎÒâ× ......