php preg_match在复杂模式匹配中的应用

preg_match 是 PHP 中一个非常强大的正则表达式函数，它可以用于在字符串中搜索与正则表达式模式匹配的子串

1. 验证电子邮件地址：

$email = "example@example.com"; $pattern = "/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/"; if (preg_match($pattern, $email)) {     echo "Email is valid"; } else {     echo "Email is invalid"; } 

2. 验证电话号码：

$phone = "123-456-7890"; $pattern = "/^\d{3}-\d{3}-\d{4}$/"; if (preg_match($pattern, $phone)) {     echo "Phone number is valid"; } else {     echo "Phone number is invalid"; } 

3. 验证 URL：

$url = "https://www.example.com"; $pattern = "/^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/"; if (preg_match($pattern, $url)) {     echo "URL is valid"; } else {     echo "URL is invalid"; } 

4. 解析 CSV 文件：

$csv = "name,age,email\nJohn,30,john@example.com\nJane,28,jane@example.com"; $pattern = "/^(.*?)\n/"; if (preg_match_all($pattern, $csv, $matches)) {     foreach ($matches[1] as $row) {         $data = explode(",", $row);         echo "Name: " . $data[0] . ", Age: " . $data[1] . ", Email: " . $data[2] . "\n";     } } 

5. 替换字符串中的特定内容：

$text = "The price of this item is $10."; $pattern = "/\$(.*?)\$/"; $replacement = "50"; $new_text = preg_replace($pattern, $replacement, $text); echo $new_text; // Output: The price of this item is 50. 

这些示例展示了 preg_match 在复杂模式匹配中的应用。正则表达式可以帮助你处理各种字符串操作，从而提高代码的可读性和可维护性。