我有代码:
<?php
$pattern = '~(?(?=hello 2)(hello 2)|hello (1))~';
$subjects = [];
$subjects[] = <<<EOD
test hello 2 test
EOD;
$subjects[] = <<<EOD
test hello 1 test
EOD;
$result = preg_match_all($pattern, $subjects[0], $matches);
assert($matches[1][0] == 'hello 2');
$result = preg_match_all($pattern, $subjects[1], $matches);
assert($matches[1][0] == '1');
我希望在一个数组中包含所有匹配项 - 数组中的2个项目(输入字符串,第一个或第二个表达式的结果),但现在我得到3个数组项(输入字符串,结果,空)或(输入字符串,空,结果)。在var转储中它是:
实际状态:
array(3) {
[0] =>
array(1) {
[0] =>
string(7) "hello 2"
}
[1] =>
array(1) {
[0] =>
string(7) "hello 2"
}
[2] =>
array(1) {
[0] =>
string(0) ""
}
}
array(3) {
[0] =>
array(1) {
[0] =>
string(7) "hello 1"
}
[1] =>
array(1) {
[0] =>
string(0) ""
}
[2] =>
array(1) {
[0] =>
string(1) "1"
}
}
我想:
array(2) {
[0] =>
array(1) {
[0] =>
string(7) "hello 2"
}
[1] =>
array(1) {
[0] =>
string(7) "hello 2"
}
}
array(2) {
[0] =>
array(1) {
[0] =>
string(7) "hello 1"
}
[1] =>
array(1) {
[0] =>
string(1) "1"
}
}
答案 0 :(得分:1)
您需要将{em>分支重置与?|
:
$pattern = '~(?|(?=hello 2)(hello 2)|hello (1))~';
请参阅IDEONE demo
这样,您将避免非参与组作为结果匹配数组的一部分出现。
有关详细信息,请参阅regular-expressions.info上的Branch Reset Groups。