Question

说我有类似的东西：

$content = " some text [TAG_123] and other text";

我想匹配[TAG_123]。

更准确一点：[后跟一个大写A-Z，后跟零或多个0-9A-Z_，后跟]。

我试过了：

$reg = "/\[[A-Z]+[0-9A-Z_]*/"; // => this match [TAG_123

$reg = "/\[[A-Z]+[0-9A-Z_]*\]/"; // => this doesn't work ???

Answer 1

[A-Z]：1个字母，A-Z
[A-Z0-9_]*：0或更多，A-Z，0-9或_
\[和\]：字面上匹配[和]

$content = " some text [TAG_123] and other text";
if (preg_match('/\[[A-Z][0-9A-Z_]*\]/', $content, $matches)) {
    print_r($matches); // $matches[0] includes [TAG_123]
}

Answer 2

您忘记在正则表达式中包含下划线：

$reg = "/\[[A-Z]+[0-9A-Z]*/"; // => this matches [TAG and not [TAG_123

此外，您需要从+中移除[A-Z]，因为它只需要一次。

<?php
$content = " some text [TAG_123] and other text";

$regs="/\[[A-Z][0-9A-Z]*/";
preg_match($regs, $content, $matches);
print_r($matches);

$regs="/\[[A-Z][0-9A-Z_]*/";
preg_match($regs, $content, $matches);
print_r($matches);

$regs="/\[[A-Z][0-9A-Z_]*\]/";
preg_match($regs, $content, $matches);
print_r($matches);

结果

    Array ( [0] => [TAG )
    Array ( [0] => [TAG_123 )
    Array ( [0] => [TAG_123] )

RegEx匹配balise []与A Z0-9内部

2 个答案: