Table of Contents
转义字符串:
分割合并字符串
填充、替换字符串
处理子字符串
查找字符串
去除字符串
转换大小写
其他转换字符串
加密字符串
输出字符串
获取字符串信息
比较字符串
Home Backend Development PHP Tutorial PHP string function summary

PHP string function summary

Apr 02, 2018 am 09:26 AM
php function string

本篇文章介绍了关于php 字符串函数的总结 ,给大家分享一下,有兴趣的朋友可以看一下


转义字符串:

  • addslashes — 使用反斜线引用字符串

  • stripslashes — 反引用一个引用字符串

  • htmlentities —将字符转换为 HTML 转义字符

  • html_entity_decode — Convert all HTML entities to their applicable characters

$orig = "I&#39;ll \"walk\" the <b>dog</b> now";$a = htmlentities($orig);$b = html_entity_decode($a);echo "用htmlentities转义输出的:".$a; 
echo "<br/>";echo "<br/>";echo "用html_entity_decode反转义输出的:".$b;
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PHP string function summary

  • htmlspecialchars— 将特殊字符转换为 HTML 实体

  • htmlspecialchars_decode— 将特殊的 HTML 实体转换回普通字符

htmlentities()各方面都和 htm

lspecialchars() 一样, 除了 htmlentities() 会转换所有具有 HTML 实体的字符,可能导致中文乱码,需要注意encoding参数的添加

  • get_html_translation_table — 返回使用 htmlspecialcharshtmlentities 后的转换表

  • quotemeta — 转义元字符集

分割合并字符串

  • chunk_split — 将字符串分割成小块

<?php//将 1234567890 转换成 1,234,567,890 每 3 位用逗号隔开的形式。$str = 1234567890;//字符串反转$rstr = strrev($str);$rstr = chunk_split($rstr,3,&#39;,&#39;);$str = strrev($rstr);//去除左边的&#39;,&#39;$str = ltrim($str,&#39;,&#39;);echo $str;
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  • explode —使用一个字符串分割另一个字符串

  • implode — 将一个一维数组的值转化为字符串

  • str_split — 将字符串转换为数组

填充、替换字符串

  • str_pad —使用另一个字符串填充字符串为指定长度

  • str_repeat — 重复一个字符串

  • str_replace —子字符串替换

  • str_ireplace — str_replace 的忽略大小写版本

  • strtr — 转换指定字符

处理子字符串

  • substr — 返回字符串的子串

  • substr_count — 计算字串出现的次数

  • substr_replace— 替换字符串的子串

查找字符串

  • strstr — 查找字符串的首次出现

  • stristr — strstr 函数的忽略大小写版本

  • strpos — 查找字符串首次出现的位置

  • stripos —查找字符串首次出现的位置(不区分大小写)

  • strrpos —计算指定字符串在目标字符串中最后一次出现的位置

  • strripos —计算指定字符串在目标字符串中最后一次出现的位置(不区分大小写)

去除字符串

  • ltrim — 删除字符串开头的空白字符(或其他字符)

  • rtrim — 删除字符串末端的空白字符(或者其他字符)

  • trim — 去除字符串首尾处的空白字符(或者其他字符)

  • strip_tags — 从字符串中去除 HTML 和 PHP 标记

转换大小写

  • lcfirst —使一个字符串的第一个字符小写

  • ucfirst — 将字符串的首字母转换为大写

  • strtolower — 将字符串转化为小写

  • strtoupper — 将字符串转化为大写

  • ucwords — 将字符串中每个单词的首字母转换为大写

其他转换字符串

  • nl2br — 在字符串所有新行之前插入HTML 换行标记

  • number_format — 以千位分隔符方式格式化一个数字

$number = 123456.56;//默认千位符用&#39;,&#39; 小数点用&#39;.&#39;$format_number = number_format($number,1);echo $format_number;
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PHP string function summary

  • strrev — 反转字符串

  • ip2long — 将 IPV4 的字符串互联网协议转换成长整型数字

  • long2ip — 将长整型转化为字符串形式带点的互联网标准格式地址(IPV4)

加密字符串

  • crypt — 单向字符串散列

<?phpif (CRYPT_STD_DES == 1) {    echo &#39;Standard DES: &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;rl&#39;) . "\n";
}if (CRYPT_EXT_DES == 1) {    echo &#39;Extended DES: &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;_J9..rasm&#39;) . "\n";
}if (CRYPT_MD5 == 1) {    echo &#39;MD5:          &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;$1$rasmusle$&#39;) . "\n";
}if (CRYPT_BLOWFISH == 1) {    echo &#39;Blowfish:     &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;$2a$07$usesomesillystringforsalt$&#39;) . "\n";
}if (CRYPT_SHA256 == 1) {    echo &#39;SHA-256:      &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;$5$rounds=5000$usesomesillystringforsalt$&#39;) . "\n";
}if (CRYPT_SHA512 == 1) {    echo &#39;SHA-512:      &#39; . crypt(&#39;rasmuslerdorf&#39;, &#39;$6$rounds=5000$usesomesillystringforsalt$&#39;) . "\n";
}
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  • md5 — 计算字符串的 MD5 散列值

  • sha1 — 计算字符串的 sha1 散列值

输出字符串

  • echo — 输出一个或多个字符串

  • print — 输出字符串

  • printf — 输出格式化字符串

获取字符串信息

  • chr — 返回 ASCII 码值指定的字符

  • ord — 返回字符的 ASCII 码值

  • parse_str — 将字符串解析成多个变量

<?php$str = "first=value&arr[]=foo+bar&arr[]=baz";// 推荐用法parse_str($str, $output);echo $output[&#39;first&#39;];  // valueecho "<br/>";echo $output[&#39;arr&#39;][0]; // foo barecho "<br/>";echo $output[&#39;arr&#39;][1]; // baz
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PHP string function summary

  • strlen — 获取字符串长度

比较字符串

  • strcmp — 二进制安全字符串比较

  • strcasecmp — 二进制安全比较字符串(不区分大小写)

  • strnatcmp — 使用自然排序算法比较字符串

相关推荐:

PHP常用数组和字符串函数总结

PHP字符串转数组和数组转字符串函数讲解

php输出格式化的字符串函数printf()



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