How to use regular expression in php to match only ID cards
php’s regular expression that only matches ID cards is “/\b\d{17}[\dX]\b/”. How to use: 1. Define a string variable containing the ID number. "$string", the regular expression is stored in the "$pattern" variable; 2. Use the "preg_match()" function to match the string; 3. Use the "if" statement to check whether the ID number is matched; 4. If an ID number is matched, use the "echo" statement to print the matched ID number.

The operating environment of this article: Windows 10 system, php8.1.3 version, dell g3 computer.
When using regular expressions to match ID number, you can try the following steps to solve the problem:
Determine the format of the ID number: The format of the ID number may vary, It depends on which country or region you are in. In China, ID numbers usually consist of 18 digits, and the last digit may be a number or the letter X (used to represent 10).
Write a regular expression pattern: Based on the format of the ID number, write a regular expression pattern that can match the ID number. For Chinese ID numbers, the regular expression pattern can be: /\b\d{17}[\dX]\b/.
\b means matching word boundaries to ensure that the entire ID number is matched.
\d means match any number.
{17} means that the previous element (\d) is repeated 17 times.
[\dX] means matching any number or letter X.
\b Used to ensure again that the entire ID number is matched.
Using regular expressions in PHP: Suppose you want to match an ID number in a string, you can write the code like this:
$string="这是一个身份证号码:123456789012345678X";
$pattern='/\b\d{17}[\dX]\b/';
if(preg_match($pattern,$string,$matches)){
//进一步处理匹配到的身份证号码
echo"匹配到的身份证号码:".$matches[0];
}else{
echo"未找到匹配的身份证号码";
}This code is a match using regular expressions Example of ID number. Let me explain the function and steps of this code step by step:
Step 1: Define the string and regular expression pattern
defines a character that contains the ID number String variable $string. The regular expression pattern is stored in the $pattern variable and is used to match ID numbers.
Step 2: Perform regular expression matching
Use the preg_match() function to match strings. This function accepts three parameters: the regular expression pattern, the string to search for, and an optional variable to store the match results.
Step 3: Check whether the ID number is matched
Check whether the ID number is matched through the if statement. If the match is successful, the next step will be processed; otherwise, the code in the else statement will be executed.
Step 4: Process the matched ID number
If the ID number is matched, use the echo statement to print the matched ID number.
Please note that this is just a simple example, and the specific implementation depends on your specific needs and code architecture.
The above is the detailed content of How to use regular expression in php to match only ID cards. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
A Simple Guide to PHP Setup
Jul 18, 2025 am 04:25 AM
The key to setting up PHP is to clarify the installation method, configure php.ini, connect to the web server and enable necessary extensions. 1. Install PHP: Use apt for Linux, Homebrew for Mac, and XAMPP recommended for Windows; 2. Configure php.ini: Adjust error reports, upload restrictions, etc. and restart the server; 3. Use web server: Apache uses mod_php, Nginx uses PHP-FPM; 4. Install commonly used extensions: such as mysqli, json, mbstring, etc. to support full functions.
Commenting Out Code in PHP
Jul 18, 2025 am 04:57 AM
There are three common methods for PHP comment code: 1. Use // or # to block one line of code, and it is recommended to use //; 2. Use /.../ to wrap code blocks with multiple lines, which cannot be nested but can be crossed; 3. Combination skills comments such as using /if(){}/ to control logic blocks, or to improve efficiency with editor shortcut keys, you should pay attention to closing symbols and avoid nesting when using them.
Tips for Writing PHP Comments
Jul 18, 2025 am 04:51 AM
The key to writing PHP comments is to clarify the purpose and specifications. Comments should explain "why" rather than "what was done", avoiding redundancy or too simplicity. 1. Use a unified format, such as docblock (/*/) for class and method descriptions to improve readability and tool compatibility; 2. Emphasize the reasons behind the logic, such as why JS jumps need to be output manually; 3. Add an overview description before complex code, describe the process in steps, and help understand the overall idea; 4. Use TODO and FIXME rationally to mark to-do items and problems to facilitate subsequent tracking and collaboration. Good annotations can reduce communication costs and improve code maintenance efficiency.
Improving Readability with Comments
Jul 18, 2025 am 04:46 AM
The key to writing good comments is to explain "why" rather than just "what was done" to improve the readability of the code. 1. Comments should explain logical reasons, such as considerations behind value selection or processing; 2. Use paragraph annotations for complex logic to summarize the overall idea of functions or algorithms; 3. Regularly maintain comments to ensure consistency with the code, avoid misleading, and delete outdated content if necessary; 4. Synchronously check comments when reviewing the code, and record public logic through documents to reduce the burden of code comments.
Writing Effective PHP Comments
Jul 18, 2025 am 04:44 AM
Comments cannot be careless because they want to explain the reasons for the existence of the code rather than the functions, such as compatibility with old interfaces or third-party restrictions, otherwise people who read the code can only rely on guessing. The areas that must be commented include complex conditional judgments, special error handling logic, and temporary bypass restrictions. A more practical way to write comments is to select single-line comments or block comments based on the scene. Use document block comments to explain parameters and return values at the beginning of functions, classes, and files, and keep comments updated. For complex logic, you can add a line to the previous one to summarize the overall intention. At the same time, do not use comments to seal code, but use version control tools.
Learning PHP: A Beginner's Guide
Jul 18, 2025 am 04:54 AM
TolearnPHPeffectively,startbysettingupalocalserverenvironmentusingtoolslikeXAMPPandacodeeditorlikeVSCode.1)InstallXAMPPforApache,MySQL,andPHP.2)Useacodeeditorforsyntaxsupport.3)TestyoursetupwithasimplePHPfile.Next,learnPHPbasicsincludingvariables,ech
Quick PHP Installation Tutorial
Jul 18, 2025 am 04:52 AM
ToinstallPHPquickly,useXAMPPonWindowsorHomebrewonmacOS.1.OnWindows,downloadandinstallXAMPP,selectcomponents,startApache,andplacefilesinhtdocs.2.Alternatively,manuallyinstallPHPfromphp.netandsetupaserverlikeApache.3.OnmacOS,installHomebrew,thenrun'bre
Mastering PHP Block Comments
Jul 18, 2025 am 04:35 AM
PHPblockcommentsareusefulforwritingmulti-lineexplanations,temporarilydisablingcode,andgeneratingdocumentation.Theyshouldnotbenestedorleftunclosed.BlockcommentshelpindocumentingfunctionswithPHPDoc,whichtoolslikePhpStormuseforauto-completionanderrorche


