任何人都知道如何修改下面的刮刀以获得所需的结果：
Array ( [0] => Gold_Needle [1] => Silver_Needle )
代码可以在线运行@http://ideone.com/QATj5a
结果是：
Array ( [0] => this is a bunch of hay hay1= Gold_Needle [1] => Silver_Needle )
所需结果为：
Array ( [0] => Gold_Needle [1] => Silver_Needle )
使用$starts和$ends数组构建如下的前瞻正则表达式：
(hay1='h*'K(?:.(?!hay1))*?(?= hay=Gold))|(hay2='h*'K(?:.(?!hay2))*?(?= hay=Silver))
RegEx演示
代码演示
代码：
$haystack='Data set 1: hay2= this is a bunch of hay hay1= Gold_Needle hay=Gold
Data Set 2: hay2=Silver_Needle hay=Silver';
$needle1_Begin='hay1=';
$needle2_Begin='hay2=';
$needle1_End='hay=Gold';
$needle2_End='hay=Silver';
$starts = array($needle1_Begin,$needle2_Begin);
$ends = array($needle1_End,$needle2_End);
$re = array_reduce($starts, function($res, $e) use (&$ends) {
$res .= '(' . $e . ''h*'K(?:.(?!' . $e . '))*?(?= ' . current($ends) . '))|';
next($ends); return $res;} );
$re = '/' . substr($re, 0, -1) . '/';
if (preg_match_all($re, $haystack, $m))
print_r($m[0]);
输出：
Array
(
[0] => Gold_Needle
[1] => Silver_Needle
)