Home Backend Development PHP Tutorial empty String exception prompt string common functions

empty String exception prompt string common functions

Jul 28, 2016 am 08:25 AM

//指定字符列表 将列表中包含的所有字符 全部转义<br>addcslashes(string $str,string $charlist);<br>echo addcslashes('foo[ ]','A..z'); <br>//输出:\f\o\o\[ \]<br>//将字符串foo[ ] ascii码在A-z之间的所有字符 全部转义 <br>//注意: A-z 不能写成z-A ascii码 必须 从小到大<br>//echo addcslashes('foo['.']','z..A');<br>// 输出:\zoo['\.']<br>//去除字符串中的反斜线<br>stripcslashes<br>$STR = <<<EOF<br>\\\\<br>EOF;<br>echo $STR;<br>//<br>echo stripcslashes($STR);<br>/ 四个转义字符转义为1个/<br><em><br></em>//通过获取php.ini magic_quotes_sybase的值 对' " \进行转义<br>addslashes(string $str)<br>magic_quotes_sybase = Off<br>$str = '\'"\ ';<br>echo addslashes($str);<br>\'\"\\ 
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magic_quotes_sybase = On<br>$str = '\'"\ ';<br>echo addslashes($str);<br>''"\test.php?name='liukai'<em>if(!get_magic_quotes_gpc()){ //检测php。ini 是否开启了对get post cookie自动转义 gpc get post cookie 的缩</em><em>  foreach($_GET as &$val){</em><em>    $val = addslashes($val); //将get数组自动转</em><em>  }</em><em>}</em>
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<em><br></em>//根据当前magic_quotes_runtime的值 去除由经过addslashes操作的字符串添加的转义字符<br>stripaddslashes(string $str)<br>magic_quotes_sybase = On<br>$str = "''";<br>echo stripaddslashes($str);<br>输出 ’<br>magic_quotes_sybase = Off<br>$str = "\'\"\\";<br>echo stripaddslashes($str);<br>输出 ’"\<em><br></em>//rtrim的别名函数 删除字符串右边指定字符列表内的所有字符 默认是字符列表只有空格<br>chop(string $str[,string $charlist])<br>var_dump(chop(' 123   '));<br>输出string(4) 123<br>var_dump(' 123 c','c');<br>输出string(5) 123 <br>var_dump(' 123 asw','swa');<br>输出string(5) 123 <br><em><br></em><br>//返回该ascii码的指定字符<br>chr(int $ascii)<br>echo chr(97);<br>输出 a<em><br><em><em><em><em><em><br></em></em></em></em></em></em>//使用此函数将字符串分割成小块非常有用。例如将 base64_encode() 的输出转换成符合 RFC 2045 语义的字符串。它会在每 <tt>chunklen</tt> (默认为 76)个字符后边插入 <tt>end</tt> (默认为“\r\n”)。此函数会返回新的字符串,而不会修改原有字符串。<br>chunk_split(string $body,[, <span><span>int <tt>$chunklen</tt> [, <span><span>string <tt>$end</tt> ]] )</span></span></span></span>
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$new_string = chunk_split(base64_encode($data));  //将base64_encode() 的输出转换成符合 RFC 2045 语义的字符串。<br>//返回字符串所用字符的信息<br>统计String中每个字节值(0..255)出现的次数,使用多种模式返回结果。可选参数mode默认值为0。根据不同的mode,count_chars()返回下列不同的结果:<br>0 - 以所有的每个字节值为键名,出现次数作为值的数组。<br>1 - 与0相同,但只列出出现次数大于零的字节值。<br>2 - 与0相同,但只列出出现次数等于零的字节值。<br>3 - 返回由所有使用了的字节值组成的字符串。<br>4 - 返回由所有未使用的字节值组成的字符串。<br>count_chars(string $str[,int $mode])
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以上就介绍了empty String异常提示 string 常用函数,包括了empty String异常提示方面的内容,希望对PHP教程有兴趣的朋友有所帮助。

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