字符串函数-大小写转化&html标签关联

<?php// strtolower()字符串转化为小写var_dump(strtolower($str));echo "<hr/>";// strtoupper()字符串转化为大写var_dump(strtoupper($str));echo "<hr/>";// ucfirst()字符串首字母大写$str3="hellow world nihao a";var_dump(ucfirst($str3));echo "<hr/>";// ucwords()字符串每个单词首字符转为大写var_dump(ucwords($str3));echo "<hr/>";// htmlentities()把字符转为html实体$str5="<b>la''la</b><h1>haha</h1>";var_dump(htmlentities($str5));echo "<hr/>";// htmlspecialchars()预定义字符穿转为html编码var_dump(htmlspecialchars($str5));echo "<hr/>";// nl2br()\n转移为<br>标签$str6="hoho\nlalala";echo $str6;echo "<hr/>";echo nl2br($str6);echo "<hr/>";var_dump($str6);var_dump(nl2br($str6));echo "<hr/>";// strip_tags()剥去htmlentities.xml以及PHP的标签var_dump(strip_tags($str5));echo "<hr/>";// addcslashes()在指定的字符前添加反斜线转移字符串中字符var_dump(addcslashes($str5,'a'));echo "<hr/>";// stripcsslashes()删除由addcslashes()添加的反斜线echo stripcslashes("\ahelow\aiaam\najack");// addslashes()指定预定义字符前添加反斜线var_dump(addslashes($str5));echo "<hr/>";// stripslashers()删除由addslashers()添加的转义字符var_dump(stripslashes("\'ahelow\aiaam\'najack"));echo "<hr/>";// quotemeta()在字符串中某些预定义的字符前添加反斜线var_dump(quotemeta("aa'asd'//asd./..()\\"));echo "<hr/>";// chr()从指定的ASCII值返回字符var_dump(chr(100));echo "<hr/>";// ord()返回字符串第一个字符的ASCII值var_dump(ord("asdd ss")); echo "<hr/>";