试试下面的代码
$str = 'test0[A]test1[B][C]test2[/B][/C][/A] [A][B]test3[/B][/A] test4';
$matches = array();
// Find and remove the unneeded strings
$pattern = '/(\[A\]|\[B\]|\[C\])[^\[]*(\[A\]|\[B\]|\[C\])[^\[]*(\[A\]|\[B\]|\[C\])([^\[]*)(\[\/A\]|\[\/B\]|\[\/C\])[^\[]*(\[\/A\]|\[\/B\]|\[\/C\])[^\[]*(\[\/A\]|\[\/B\]|\[\/C\])/';
preg_match_all( $pattern, $str, $matches );
$stripped_str = $str;
foreach ($matches[0] as $key=>$matched_pattern) {
$matched_pattern_str = str_replace($matches[4][$key], '', $matched_pattern); // matched pattern with text between A,B,C tags removed
$stripped_str = str_replace($matched_pattern, $matched_pattern_str, $stripped_str); // replace pattern string in text with stripped pattern string
}
// Get required strings
$pattern = '/(\[A\]|\[B\]|\[C\]|\[\/A\]|\[\/B\]|\[\/C\])([^\[]+)(\[A\]|\[B\]|\[C\]|\[\/A\]|\[\/B\]|\[\/C\])/';
preg_match_all( $pattern, $stripped_str, $matches );
$required_strings = array();
foreach ($matches[2] as $match) {
if (trim($match) != '') {
$required_strings[] = $match;
}
}
// Special case, possible string on start and end
$pattern = '/^([^\[]*)(\[A\]|\[B\]|\[C\]).*(\[\/A\]|\[\/B\]|\[\/C\])([^\[]*)$/';
preg_match( $pattern, $stripped_str, $matches );
if (trim($matches[1]) != '') {
$required_strings[] = $matches[1];
}
if (trim($matches[4]) != '') {
$required_strings[] = $matches[4];
}
print_r($required_strings);