php中字符如何实现大小写转换-masalah PHP-php.cn

在php中可以通过“mb_strtoupper”和“mb_strtolower”函数实现大小写转换，其中“mb_strtoupper”函数用于将字符串转化为大写，而“mb_strtolower”函数则用于将字符串转化为小写。

推荐：《 PHP教程 》

strtoupper()、strtolower()、ucfirst()、ucfirst()、ucwords()、mb_strtoupper()、mb_strtolower()和mb_convert_case()这八个函数的区别和联系：

函数名称

使用范围

功能

strtoupper

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4 、 PHP5

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 将字符串转化为大写

strtolower

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4 、 PHP5

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 将字符串转化为小写

ucfirst

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4 、 PHP5

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 将字符串的首字母转化为大写

lcfirst

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP5>= 5.3.0

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 将字符串的首字母转化为小写

ucwords

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4 、 PHP5

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 将字符串中每个单词的首字符转化为大写

mb_strtoupper

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4>=4.3.0,PHP 5

将字符串转化为大写（与 strtoupper 函数有区别）

mb_strtolower

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4>=4.3.0,PHP 5

将字符串转化为小写（与 strtolower 函数有区别）

mb_convert_case

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 99pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="132"> PHP4>=4.3.0,PHP 5

<td style="border-right: windowtext 1pt solid; padding-right: 5.4pt; border-top: #ece9d8; padding-left: 5.4pt; padding-bottom: 0cm; border-left: #ece9d8; width: 243pt; padding-top: 0cm; border-bottom: windowtext 1pt solid; background-color: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt;" valign="top" width="324"> 按照不同的模式对字符串进行转换