如何使用php正则表达式进行字符集匹配?
php 正则表达式提供了一系列字符集匹配符,用于匹配特定的字符模式:【1】方括号 []: 匹配指定字符集内的任何字符;【2】1: 匹配指定字符集之外的字符;【3】d: 匹配数字或与 [0-9] 等价;【4】d: 匹配非数字或与 2 等价;【5】w: 匹配字母数字或与 [a-za-z0-9_] 等价;【6】w: 匹配非字母数字或与 3 等价。... ↩0-9 ↩a-za-z0-9_ ↩
PHP 中正则表达式字符集匹配
正则表达式是用于匹配和处理文本的一种强大工具。PHP 提供了一组字符集匹配符,允许您匹配字符串中符合特定模式的字符。
字符集匹配符
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实战案例
1. 匹配数字(d)
$pattern = '/d/';$subject = '12345';$matches = preg_match_all($pattern, $subject, $matches);print_r($matches);
输出:
Array( [0] => Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 ))
2. 匹配非数字(D)
$pattern = '/D/';$subject = 'Test123';$matches = preg_match_all($pattern, $subject, $matches);print_r($matches);
输出:
Array( [0] => Array ( [0] => T [1] => e [2] => s [3] => t ))
3. 匹配字母数字(w)
$pattern = '/w/';$subject = 'My_Username123';$matches = preg_match_all($pattern, $subject, $matches);print_r($matches);
输出:
Array( [0] => Array ( [0] => M [1] => y [2] => _ [3] => U [4] => s [5] => e [6] => r [7] => n [8] => a [9] => m [10] => e [11] => 1 [12] => 2 [13] => 3 ))
4. 匹配非字母数字(W)
$pattern = '/W/';$subject = 'My Username!@#$%^&*()';$matches = preg_match_all($pattern, $subject, $matches);print_r($matches);
输出:
Array( [0] => Array ( [0] => ! [1] => @ [2] => # [3] => $ [4] => % [5] => ^ [6] => & [7] => * [8] => ( [9] => ) [10] => ))
- 0-9 ↩
- a-zA-Z0-9_ ↩