php字符串处理之全角半角转换
半角全角的处理是字符串处理的常见问题，本文尝试为大家提供一个思路。
一、概念
全角字符unicode编码从65281~65374 （十六进制 0xFF01 ~ 0xFF5E）
半角字符unicode编码从33~126 （十六进制 0x21~ 0x7E）
空格比较特殊,全角为 12288（0x3000）,半角为 32 （0x20）
而且除空格外,全角/半角按unicode编码排序在顺序上是对应的
所以可以直接通过用+-法来处理非空格数据,对空格单独处理
二、实现思路
1. 找到目标unicode的字符，可以使用正则表达式解决
2. 修改unicode编码
三、实现
1. 首先是两个unicode与字符的转换函数：
<span style="color: #008080;"> 1</span> <span style="color: #008000;">/*</span><span style="color: #008000;">*</span><span style="color: #008080;"> 2</span> <span style="color: #008000;"> * 将unicode转换成字符</span><span style="color: #008080;"> 3</span> <span style="color: #008000;"> * @param int $unicode</span><span style="color: #008080;"> 4</span> <span style="color: #008000;"> * @return string UTF-8字符</span><span style="color: #008080;"> 5</span> <span style="color: #008000;"> *</span><span style="color: #008000;">*/</span><span style="color: #008080;"> 6</span> <span style="color: #0000ff;">function</span> unicode2Char(<span style="color: #800080;">$unicode</span><span style="color: #000000;">){</span><span style="color: #008080;"> 7</span> <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$unicode</span> return <span style="color: #008080;">chr</span>(<span style="color: #800080;">$unicode</span><span style="color: #000000;">);</span><span style="color: #008080;"> 8</span> <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$unicode</span> return <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> >> 6) + 192) .<span style="color: #008080;"> 9</span> <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> & 63) + 128<span style="color: #000000;">);</span><span style="color: #008080;">10</span> <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$unicode</span> return <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> >> 12) + 224) .<span style="color: #008080;">11</span> <span style="color: #008080;">chr</span>(((<span style="color: #800080;">$unicode</span> >> 6) & 63) + 128) .<span style="color: #008080;">12</span> <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> & 63) + 128<span style="color: #000000;">);</span><span style="color: #008080;">13</span> <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$unicode</span> return <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> >> 18) + 240) .<span style="color: #008080;">14</span> <span style="color: #008080;">chr</span>(((<span style="color: #800080;">$unicode</span> >> 12) & 63) + 128) .<span style="color: #008080;">15</span> <span style="color: #008080;">chr</span>(((<span style="color: #800080;">$unicode</span> >> 6) & 63) + 128) .<span style="color: #008080;">16</span> <span style="color: #008080;">chr</span>((<span style="color: #800080;">$unicode</span> & 63) + 128<span style="color: #000000;">);</span><span style="color: #008080;">17</span> <span style="color: #0000ff;">return</span> <span style="color: #0000ff;">false</span><span style="color: #000000;">;</span><span style="color: #008080;">18</span> <span style="color: #000000;"> }</span><span style="color: #008080;">19</span> <span style="color: #008080;">20</span> <span style="color: #008000;">/*</span><span style="color: #008000;">*</span><span style="color: #008080;">21</span> <span style="color: #008000;"> * 将字符转换成unicode</span><span style="color: #008080;">22</span> <span style="color: #008000;"> * @param string $char 必须是UTF-8字符</span><span style="color: #008080;">23</span> <span style="color: #008000;"> * @return int</span><span style="color: #008080;">24</span> <span style="color: #008000;"> *</span><span style="color: #008000;">*/</span><span style="color: #008080;">25</span> <span style="color: #0000ff;">function</span> char2Unicode(<span style="color: #800080;">$char</span><span style="color: #000000;">){</span><span style="color: #008080;">26</span> <span style="color: #0000ff;">switch</span> (<span style="color: #008080;">strlen</span>(<span style="color: #800080;">$char</span><span style="color: #000000;">)){</span><span style="color: #008080;">27</span> <span style="color: #0000ff;">case</span> 1 : <span style="color: #0000ff;">return</span> <span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span><span style="color: #000000;">);</span><span style="color: #008080;">28</span> <span style="color: #0000ff;">case</span> 2 : <span style="color: #0000ff;">return</span> (<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{1}) & 63) |<span style="color: #008080;">29</span> ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{0}) & 31) );<span style="color: #008080;">30</span> <span style="color: #0000ff;">case</span> 3 : <span style="color: #0000ff;">return</span> (<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{2}) & 63) |<span style="color: #008080;">31</span> ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{1}) & 63) 32 ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{0}) & 15) );<span style="color: #008080;">33</span> <span style="color: #0000ff;">case</span> 4 : <span style="color: #0000ff;">return</span> (<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{3}) & 63) |<span style="color: #008080;">34</span> ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{2}) & 63) 35 ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{1}) & 63) 36 ((<span style="color: #008080;">ord</span>(<span style="color: #800080;">$char</span>{0}) & 7) );<span style="color: #008080;">37</span> <span style="color: #0000ff;">default</span> :<span style="color: #008080;">38</span> <span style="color: #008080;">trigger_error</span>('Character is not UTF-8!', <span style="color: #ff00ff;">E_USER_WARNING</span><span style="color: #000000;">);</span><span style="color: #008080;">39</span> <span style="color: #0000ff;">return</span> <span style="color: #0000ff;">false</span><span style="color: #000000;">;</span><span style="color: #008080;">40</span> <span style="color: #000000;"> }</span><span style="color: #008080;">41</span> }
2. 全角转半角
<span style="color: #008080;"> 1</span> <span style="color: #008000;">/*</span><span style="color: #008000;">*</span><span style="color: #008080;"> 2</span> <span style="color: #008000;"> * 全角转半角</span><span style="color: #008080;"> 3</span> <span style="color: #008000;"> * @param string $str</span><span style="color: #008080;"> 4</span> <span style="color: #008000;"> * @return string</span><span style="color: #008080;"> 5</span> <span style="color: #008000;"> *</span><span style="color: #008000;">*/</span><span style="color: #008080;"> 6</span> <span style="color: #0000ff;">function</span> sbc2Dbc(<span style="color: #800080;">$str</span><span style="color: #000000;">){</span><span style="color: #008080;"> 7</span> <span style="color: #0000ff;">return</span> <span style="color: #008080;">preg_replace</span><span style="color: #000000;">(</span><span style="color: #008080;"> 8</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 全角字符 </span><span style="color: #008080;"> 9</span> '/[\x{3000}\x{ff01}-\x{ff5f}]/ue',<span style="color: #008080;">10</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 编码转换</span><span style="color: #008080;">11</span> <span style="color: #008000;"> // 0x3000是空格，特殊处理，其他全角字符编码-0xfee0即可以转为半角</span><span style="color: #008080;">12</span> '($unicode=char2Unicode(\'\0\')) == 0x3000 ? " " : (($code=$unicode-0xfee0) > 256 ? unicode2Char($code) : chr($code))',<span style="color: #008080;">13</span> <span style="color: #800080;">$str</span><span style="color: #008080;">14</span> <span style="color: #000000;"> );</span><span style="color: #008080;">15</span> }
3. 半角转全角
<span style="color: #008080;"> 1</span> <span style="color: #008000;">/*</span><span style="color: #008000;">*</span><span style="color: #008080;"> 2</span> <span style="color: #008000;"> * 半角转全角</span><span style="color: #008080;"> 3</span> <span style="color: #008000;"> * @param string $str</span><span style="color: #008080;"> 4</span> <span style="color: #008000;"> * @return string</span><span style="color: #008080;"> 5</span> <span style="color: #008000;"> *</span><span style="color: #008000;">*/</span><span style="color: #008080;"> 6</span> <span style="color: #0000ff;">function</span> dbc2Sbc(<span style="color: #800080;">$str</span><span style="color: #000000;">){</span><span style="color: #008080;"> 7</span> <span style="color: #0000ff;">return</span> <span style="color: #008080;">preg_replace</span><span style="color: #000000;">(</span><span style="color: #008080;"> 8</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 半角字符 </span><span style="color: #008080;"> 9</span> '/[\x{0020}\x{0020}-\x{7e}]/ue', <span style="color: #008080;">10</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 编码转换</span><span style="color: #008080;">11</span> <span style="color: #008000;"> // 0x0020是空格，特殊处理，其他半角字符编码+0xfee0即可以转为全角</span><span style="color: #008080;">12</span> '($unicode=char2Unicode(\'\0\')) == 0x0020 ? unicode2Char（0x3000） : (($code=$unicode+0xfee0) > 256 ? unicode2Char($code) : chr($code))',<span style="color: #008080;">13</span> <span style="color: #800080;">$str</span><span style="color: #008080;">14</span> <span style="color: #000000;"> );</span><span style="color: #008080;">15</span> }
四、测试
示例代码：
<span style="color: #008080;">1</span> <span style="color: #800080;">$a</span> = 'abc12 345'<span style="color: #000000;">;</span><span style="color: #008080;">2</span> <span style="color: #800080;">$sbc</span> = dbc2Sbc(<span style="color: #800080;">$a</span><span style="color: #000000;">);</span><span style="color: #008080;">3</span> <span style="color: #800080;">$dbc</span> = sbc2Dbc(<span style="color: #800080;">$sbc</span><span style="color: #000000;">);</span><span style="color: #008080;">4</span> <span style="color: #008080;">5</span> <span style="color: #008080;">var_dump</span>(<span style="color: #800080;">$a</span>, <span style="color: #800080;">$sbc</span>, <span style="color: #800080;">$dbc</span>);
结果：
<span style="color: #008080;">1</span> <span style="color: #0000ff;">string</span>(9) "abc12 345"<span style="color: #008080;">2</span> <span style="color: #0000ff;">string</span>(27) "ａｂｃ１２ ３４５"<span style="color: #008080;">3</span> <span style="color: #0000ff;">string</span>(9) "abc12 345"
PHP in Action: Real-World Examples and ApplicationsApr 14, 2025 am 12:19 AMPHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: Creating Interactive Web Content with EaseApr 14, 2025 am 12:15 AMPHP makes it easy to create interactive web content. 1) Dynamically generate content by embedding HTML and display it in real time based on user input or database data. 2) Process form submission and generate dynamic output to ensure that htmlspecialchars is used to prevent XSS. 3) Use MySQL to create a user registration system, and use password_hash and preprocessing statements to enhance security. Mastering these techniques will improve the efficiency of web development.
PHP and Python: Comparing Two Popular Programming LanguagesApr 14, 2025 am 12:13 AMPHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
The Enduring Relevance of PHP: Is It Still Alive?Apr 14, 2025 am 12:12 AMPHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP's Current Status: A Look at Web Development TrendsApr 13, 2025 am 12:20 AMPHP remains important in modern web development, especially in content management and e-commerce platforms. 1) PHP has a rich ecosystem and strong framework support, such as Laravel and Symfony. 2) Performance optimization can be achieved through OPcache and Nginx. 3) PHP8.0 introduces JIT compiler to improve performance. 4) Cloud-native applications are deployed through Docker and Kubernetes to improve flexibility and scalability.
PHP vs. Other Languages: A ComparisonApr 13, 2025 am 12:19 AMPHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP vs. Python: Core Features and FunctionalityApr 13, 2025 am 12:16 AMPHP and Python each have their own advantages and are suitable for different scenarios. 1.PHP is suitable for web development and provides built-in web servers and rich function libraries. 2. Python is suitable for data science and machine learning, with concise syntax and a powerful standard library. When choosing, it should be decided based on project requirements.
PHP: A Key Language for Web DevelopmentApr 13, 2025 am 12:08 AMPHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
Dreamweaver CS6
Visual web development tools
WebStorm Mac version
Useful JavaScript development tools
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
Zend Studio 13.0.1
Powerful PHP integrated development environment
