我们在1、location和“:”号间不能有空格,否则会出错。
2、在用header前不能有任何的输出。
3、PHP中用header后的PHP代码还会被执行。
下面是和asp中重定向response.redirect的比较:
例1:
response.redirect "../test.asp"
header("location:../test.php");
两者区别:
asp的redirect函数可以在向客户发送头文件后起作用.
如
<ol class="dp-xml"> <li class="alt"><span><strong><font color="#006699"><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span></span></span></span></font></strong><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%response.redirect "../test.asp"%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class="alt"> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
查是PHP中用header中下例代码会报错:
<ol class="dp-xml"> <li class="alt"><span><strong><font color="#006699"><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span></span></span></span></font></strong><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span> </li> <li class="alt"> <span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../test.php"); </span> </li> <li class=""> <span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span> </li> <li class="alt"> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
只能这样:
<ol class="dp-xml"> <li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span></span></li> <li class=""> <span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../test.php"); </span> </li> <li class="alt"> <span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span> </li> <li class=""> <span></span><strong><font color="#006699"><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span></span></span></span></font></strong><span>...</span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
即PHP中用header函数之前不能向客户发送任何数据.
例2:
asp中
<ol class="dp-xml"> <li class="alt"><span><strong><font color="#006699"><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span></span></span></span></font></strong><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>% </span> </li> <li class="alt"><span>response.redirect "../a.asp" </span></li> <li class=""><span>response.redirect "../b.asp" </span></li> <li class="alt"> <span>%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class=""> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
结果是重定向a.asp文件.
php呢?
<ol class="dp-xml"> <li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span></span></li> <li class=""> <span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../a.php"); </span> </li> <li class="alt"><span>header("location:../b.php"); </span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span> </li> <li class="alt"> <span></span><strong><font color="#006699"><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></span></span></span></font></strong><span> </span> </li> </ol>
我们发现它重定向b.php.
原来在asp中执行redirect后不会再执行后面的代码.
而php在执行header后,继续执行下面的代码.
在这方面上php中的header重定向不如asp中的重定向.有时我们要重定向后,不能执行后面的代码:
一般地我们用
<ol class="dp-xml"> <li class="alt"><span><span>if(...) </span></span></li> <li class=""><span>header("..."); </span></li> <li class="alt"><span>else </span></li> <li class=""><span>{ </span></li> <li class="alt"><span>... </span></li> <li class=""><span>} </span></li> </ol>
但是我们可以简单的用下面的方法:
<ol class="dp-xml"> <li class="alt"><span><span>if(...) </span></span></li> <li class=""><span>{ header("...");exit();} </span></li> </ol>
PHP中用header还要注意的是,如果是用Unicode(UTF-8)编码时也会出现问题,需要调整缓存设置.
<ol class="dp-xml"> <li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span>[</span><span class="attribute"><font color="#ff0000">email</font></span><span>=%@]%@</span><span class="attribute"><font color="#ff0000">LANGUAGE</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"VBSCRIPT[/email]"</font></span><span> </span><span class="attribute"><font color="#ff0000">CODEPAGE</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"936"</font></span><span>%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%if Request.ServerVariables("SERVER_NAME")="s.jb51.net" then </span> </li> <li class="alt"><span>response.redirect "news/index.htm" </span></li> <li class=""> <span>else%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class="alt"> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%end if%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class=""> <span></span><strong><font color="#006699"><span class="tag"><span class="tag-name">script</span><span class="tag">></span></span></font></strong><span> </span> </li> <li class="alt"> <span>var </span><span class="attribute"><font color="#ff0000">url</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">location</font></span><span>.href; </span> </li> <li class=""> <span>if(url.indexOf('http://www.jb51.net/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/index/index.htm'</font></span><span>; </span> </li> <li class="alt"> <span>if(url.indexOf('http://www.kanshule.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/index1/index.htm'</font></span><span>; </span> </li> <li class=""> <span>if(url.indexOf('http://www.shouji17.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/cn/index.asp'</font></span><span>; </span> </li> <li class="alt"> <span>if(url.indexOf('http://www.baidu.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/cn/index.asp'</font></span><span>; </span> </li> <li class=""> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">script</span><span class="tag">></span></font></strong><span> </span> </li> </ol>

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

查找方法:1、用strpos(),语法“strpos("字符串值","查找子串")+1”;2、用stripos(),语法“strpos("字符串值","查找子串")+1”。因为字符串是从0开始计数的,因此两个函数获取的位置需要进行加1处理。


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