PHP 5 String 函数

蔚落 2024-04-07 13:26 58阅读 0赞

### PHP 5 String 函数 ###

PHP String 函数是 PHP 核心的组成部分。无需安装即可使用这些函数。

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<table> 
 <tbody> 
  <tr> 
   <th>函数</th> 
   <th>描述</th> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-addcslashes.html" title="addcslashes()" rel="nofollow">addcslashes()</a></td> 
   <td>返回在指定的字符前添加反斜杠的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-addslashes.html" title="addslashes()" rel="nofollow">addslashes()</a></td> 
   <td>返回在预定义的字符前添加反斜杠的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-bin2hex.html" title="bin2hex()" rel="nofollow">bin2hex()</a></td> 
   <td>把 ASCII 字符的字符串转换为十六进制值。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-chop.html" title="chop()" rel="nofollow">chop()</a></td> 
   <td>移除字符串右侧的空白字符或其他字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-chr.html" title="chr()" rel="nofollow">chr()</a></td> 
   <td>从指定 ASCII 值返回字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-chunk-split.html" title="chunk_split()" rel="nofollow">chunk_split()</a></td> 
   <td>把字符串分割为一连串更小的部分。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-convert-cyr-string.html" title="convert_cyr_string()" rel="nofollow">convert_cyr_string()</a></td> 
   <td>把字符串由一种 Cyrillic 字符集转换成另一种。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-convert-uudecode.html" title="convert_uudecode()" rel="nofollow">convert_uudecode()</a></td> 
   <td>对 uuencode 编码的字符串进行解码。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-convert-uuencode.html" title="convert_uuencode()" rel="nofollow">convert_uuencode()</a></td> 
   <td>使用 uuencode 算法对字符串进行编码。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-count-chars.html" title="count_chars()" rel="nofollow">count_chars()</a></td> 
   <td>返回字符串所用字符的信息。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-crc32.html" title="crc32()" rel="nofollow">crc32()</a></td> 
   <td>计算一个字符串的 32 位 CRC（循环冗余校验）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-crypt.html" title="crypt()" rel="nofollow">crypt()</a></td> 
   <td>单向的字符串加密法（hashing）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-echo.html" title="echo()" rel="nofollow">echo()</a></td> 
   <td>输出一个或多个字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-explode.html" title="explode()" rel="nofollow">explode()</a></td> 
   <td>把字符串打散为数组。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-fprintf.html" title="fprintf()" rel="nofollow">fprintf()</a></td> 
   <td>把格式化的字符串写入到指定的输出流。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-get-html-translation-table.html" title="get_html_translation_table()" rel="nofollow">get_html_translation_table()</a></td> 
   <td>返回 htmlspecialchars() 和 htmlentities() 使用的翻译表。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-hebrev.html" title="hebrev()" rel="nofollow">hebrev()</a></td> 
   <td>把希伯来（Hebrew）文本转换为可见文本。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-hebrevc.html" title="hebrevc()" rel="nofollow">hebrevc()</a></td> 
   <td>把希伯来（Hebrew）文本转换为可见文本，并把新行（\n）转换为 &lt;br&gt;。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-hex2bin.html" title="hex2bin()" rel="nofollow">hex2bin()</a></td> 
   <td>把十六进制值的字符串转换为 ASCII 字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-html-entity-decode.html" title="html_entity_decode()" rel="nofollow">html_entity_decode()</a></td> 
   <td>把 HTML 实体转换为字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-htmlentities.html" title="htmlentities()" rel="nofollow">htmlentities()</a></td> 
   <td>把字符转换为 HTML 实体。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-htmlspecialchars-decode.html" title="htmlspecialchars_decode()" rel="nofollow">htmlspecialchars_decode()</a></td> 
   <td>把一些预定义的 HTML 实体转换为字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-htmlspecialchars.html" title="htmlspecialchars()" rel="nofollow">htmlspecialchars()</a></td> 
   <td>把一些预定义的字符转换为 HTML 实体。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-implode.html" title="implode()" rel="nofollow">implode()</a></td> 
   <td>返回一个由数组元素组合成的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-join.html" title="join()" rel="nofollow">join()</a></td> 
   <td>implode() 的别名。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-lcfirst.html" title="lcfirst()" rel="nofollow">lcfirst()</a></td> 
   <td>把字符串中的首字符转换为小写。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-levenshtein.html" title="levenshtein()" rel="nofollow">levenshtein()</a></td> 
   <td>返回两个字符串之间的 Levenshtein 距离。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-localeconv.html" title="localeconv()" rel="nofollow">localeconv()</a></td> 
   <td>返回本地数字及货币格式信息。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-ltrim.html" title="ltrim()" rel="nofollow">ltrim()</a></td> 
   <td>移除字符串左侧的空白字符或其他字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-md5.html" title="md5()" rel="nofollow">md5()</a></td> 
   <td>计算字符串的 MD5 散列。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-md5-file.html" title="md5_file()" rel="nofollow">md5_file()</a></td> 
   <td>计算文件的 MD5 散列。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-metaphone.html" title="metaphone()" rel="nofollow">metaphone()</a></td> 
   <td>计算字符串的 metaphone 键。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-money-format.html" title="money_format()" rel="nofollow">money_format()</a></td> 
   <td>返回格式化为货币字符串的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-nl-langinfo.html" title="nl_langinfo()" rel="nofollow">nl_langinfo()</a></td> 
   <td>返回指定的本地信息。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-nl2br.html" title="nl2br()" rel="nofollow">nl2br()</a></td> 
   <td>在字符串中的每个新行之前插入 HTML 换行符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-number-format.html" title="number_format()" rel="nofollow">number_format()</a></td> 
   <td>通过千位分组来格式化数字。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-ord.html" title="ord()" rel="nofollow">ord()</a></td> 
   <td>返回字符串中第一个字符的 ASCII 值。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-parse-str.html" title="parse_str()" rel="nofollow">parse_str()</a></td> 
   <td>把查询字符串解析到变量中。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-print.html" title="print()" rel="nofollow">print()</a></td> 
   <td>输出一个或多个字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-printf.html" title="printf()" rel="nofollow">printf()</a></td> 
   <td>输出格式化的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-quoted-printable-decode.html" title="quoted_printable_decode()" rel="nofollow">quoted_printable_decode()</a></td> 
   <td>把 quoted-printable 字符串转换为 8 位字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-quoted-printable-encode.html" title="quoted_printable_encode()" rel="nofollow">quoted_printable_encode()</a></td> 
   <td>把 8 位字符串转换为 quoted-printable 字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-quotemeta.html" title="quotemeta()" rel="nofollow">quotemeta()</a></td> 
   <td>引用元字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-rtrim.html" title="rtrim()" rel="nofollow">rtrim()</a></td> 
   <td>移除字符串右侧的空白字符或其他字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-setlocale.html" title="setlocale()" rel="nofollow">setlocale()</a></td> 
   <td>设置地区信息（地域信息）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-sha1.html" title="sha1()" rel="nofollow">sha1()</a></td> 
   <td>计算字符串的 SHA-1 散列。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-sha1-file.html" title="sha1_file()" rel="nofollow">sha1_file()</a></td> 
   <td>计算文件的 SHA-1 散列。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-similar-text.html" title="similar_text()" rel="nofollow">similar_text()</a></td> 
   <td>计算两个字符串的相似度。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-soundex.html" title="soundex()" rel="nofollow">soundex()</a></td> 
   <td>计算字符串的 soundex 键。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-sprintf.html" title="sprintf()" rel="nofollow">sprintf()</a></td> 
   <td>把格式化的字符串写入一个变量中。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-sscanf.html" title="sscanf()" rel="nofollow">sscanf()</a></td> 
   <td>根据指定的格式解析来自一个字符串的输入。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-getcsv.html" title="str_getcsv()" rel="nofollow">str_getcsv()</a></td> 
   <td>把 CSV 字符串解析到数组中。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-ireplace.html" title="str_ireplace()" rel="nofollow">str_ireplace()</a></td> 
   <td>替换字符串中的一些字符（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-pad.html" title="str_pad()" rel="nofollow">str_pad()</a></td> 
   <td>把字符串填充为新的长度。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-repeat.html" title="str_repeat()" rel="nofollow">str_repeat()</a></td> 
   <td>把字符串重复指定的次数。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-replace.html" title="str_replace()" rel="nofollow">str_replace()</a></td> 
   <td>替换字符串中的一些字符（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-rot13.html" title="str_rot13()" rel="nofollow">str_rot13()</a></td> 
   <td>对字符串执行 ROT13 编码。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-shuffle.html" title="str_shuffle()" rel="nofollow">str_shuffle()</a></td> 
   <td>随机地打乱字符串中的所有字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-split.html" title="str_split()" rel="nofollow">str_split()</a></td> 
   <td>把字符串分割到数组中。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-str-word-count.html" title="str_word_count()" rel="nofollow">str_word_count()</a></td> 
   <td>计算字符串中的单词数。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strcasecmp.html" title="strcasecmp()" rel="nofollow">strcasecmp()</a></td> 
   <td>比较两个字符串（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strchr.html" title="strchr()" rel="nofollow">strchr()</a></td> 
   <td>查找字符串在另一字符串中的第一次出现。（strstr() 的别名。）</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strcmp.html" title="strcmp()" rel="nofollow">strcmp()</a></td> 
   <td>比较两个字符串（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strcoll.html" title="strcoll()" rel="nofollow">strcoll()</a></td> 
   <td>比较两个字符串（根据本地设置）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strcspn.html" title="strcspn()" rel="nofollow">strcspn()</a></td> 
   <td>返回在找到任何指定的字符之前，在字符串查找的字符数。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strip-tags.html" title="strip_tags()" rel="nofollow">strip_tags()</a></td> 
   <td>剥去字符串中的 HTML 和 PHP 标签。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-stripcslashes.html" title="stripcslashes()" rel="nofollow">stripcslashes()</a></td> 
   <td>删除由 addcslashes() 函数添加的反斜杠。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-stripslashes.html" title="stripslashes()" rel="nofollow">stripslashes()</a></td> 
   <td>删除由 addslashes() 函数添加的反斜杠。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-stripos.html" title="stripos()" rel="nofollow">stripos()</a></td> 
   <td>返回字符串在另一字符串中第一次出现的位置（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-stristr.html" title="stristr()" rel="nofollow">stristr()</a></td> 
   <td>查找字符串在另一字符串中第一次出现的位置（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strlen.html" title="strlen()" rel="nofollow">strlen()</a></td> 
   <td>返回字符串的长度。中文字符串的处理使用&nbsp;<a href="https://www.runoob.com/php/func-string-mb_strlen.html" title="mb_strlen() 函数" rel="nofollow">mb_strlen() 函数</a>。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strnatcasecmp.html" title="strnatcasecmp()" rel="nofollow">strnatcasecmp()</a></td> 
   <td>使用一种"自然排序"算法来比较两个字符串（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strnatcmp.html" title="strnatcmp()" rel="nofollow">strnatcmp()</a></td> 
   <td>使用一种"自然排序"算法来比较两个字符串（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strncasecmp.html" title="strncasecmp()" rel="nofollow">strncasecmp()</a></td> 
   <td>前 n 个字符的字符串比较（大小写不敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strncmp.html" title="strncmp()" rel="nofollow">strncmp()</a></td> 
   <td>前 n 个字符的字符串比较（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strpbrk.html" title="strpbrk()" rel="nofollow">strpbrk()</a></td> 
   <td>在字符串中搜索指定字符中的任意一个。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strpos.html" title="strpos()" rel="nofollow">strpos()</a></td> 
   <td>返回字符串在另一字符串中第一次出现的位置（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strrchr.html" title="strrchr()" rel="nofollow">strrchr()</a></td> 
   <td>查找字符串在另一个字符串中最后一次出现。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strrev.html" title="strrev()" rel="nofollow">strrev()</a></td> 
   <td>反转字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strripos.html" title="strripos()" rel="nofollow">strripos()</a></td> 
   <td>查找字符串在另一字符串中最后一次出现的位置(大小写不敏感)。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strrpos.html" title="strrpos()" rel="nofollow">strrpos()</a></td> 
   <td>查找字符串在另一字符串中最后一次出现的位置(大小写敏感)。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strspn.html" title="strspn()" rel="nofollow">strspn()</a></td> 
   <td>返回在字符串中包含的特定字符的数目。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strstr.html" title="strstr()" rel="nofollow">strstr()</a></td> 
   <td>查找字符串在另一字符串中的第一次出现（大小写敏感）。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strtok.html" title="strtok()" rel="nofollow">strtok()</a></td> 
   <td>把字符串分割为更小的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strtolower.html" title="strtolower()" rel="nofollow">strtolower()</a></td> 
   <td>把字符串转换为小写字母。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strtoupper.html" title="strtoupper()" rel="nofollow">strtoupper()</a></td> 
   <td>把字符串转换为大写字母。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-strtr.html" title="strtr()" rel="nofollow">strtr()</a></td> 
   <td>转换字符串中特定的字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-substr.html" title="substr()" rel="nofollow">substr()</a></td> 
   <td>返回字符串的一部分。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-mb_substr.html" title="mb_substr()" rel="nofollow">mb_substr()</a></td> 
   <td>返回中文字符串的一部分。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-substr-compare.html" title="substr_compare()" rel="nofollow">substr_compare()</a></td> 
   <td>从指定的开始位置（二进制安全和选择性区分大小写）比较两个字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-substr-count.html" title="substr_count()" rel="nofollow">substr_count()</a></td> 
   <td>计算子串在字符串中出现的次数。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-substr-replace.html" title="substr_replace()" rel="nofollow">substr_replace()</a></td> 
   <td>把字符串的一部分替换为另一个字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-trim.html" title="trim()" rel="nofollow">trim()</a></td> 
   <td>移除字符串两侧的空白字符和其他字符。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-ucfirst.html" title="ucfirst()" rel="nofollow">ucfirst()</a></td> 
   <td>把字符串中的首字符转换为大写。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-ucwords.html" title="ucwords()" rel="nofollow">ucwords()</a></td> 
   <td>把字符串中每个单词的首字符转换为大写。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-vfprintf.html" title="vfprintf()" rel="nofollow">vfprintf()</a></td> 
   <td>把格式化的字符串写到指定的输出流。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-vprintf.html" title="vprintf()" rel="nofollow">vprintf()</a></td> 
   <td>输出格式化的字符串。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-vsprintf.html" title="vsprintf()" rel="nofollow">vsprintf()</a></td> 
   <td>把格式化字符串写入变量中。</td> 
  </tr> 
  <tr> 
   <td><a href="https://www.runoob.com/php/func-string-wordwrap.html" title="wordwrap()" rel="nofollow">wordwrap()</a></td> 
   <td>按照指定长度对字符串进行折行处理。</td> 
  </tr> 
 </tbody> 
</table>