[英]Split an array with a regular expression
I'm wondering if it is possible to truncate an array by using a regular expression. 我想知道是否可以通过使用正则表达式截断数组。
In particular I have an array like this one: 特别是我有一个像这样的数组:
$array = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc","AaDa"...);
I have this string: 我有这个字符串:
$str = "AC";
I'd like the slice of $array
from the start to the last occurrence of a string matching /AC/
(in the sample, "AaCc" at index 5): 我想要从
$array
的切片开始到最后一个匹配/AC/
的字符串(在示例中,索引为5的“ AaCc”):
$result = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc");
How can I do this? 我怎样才能做到这一点? I thought I might use
array_slice
, but I don't know how to use a RegEx with it. 我以为可以使用
array_slice
,但是我不知道如何使用RegEx。
function split_by_contents($ary, $pattern){
if (!is_array($ary)) return FALSE; // brief error checking
// keep track of the last position we had a match, and the current
// position we're searching
$last = -1; $c = 0;
// iterate over the array
foreach ($ary as $k => $v){
// check for a pattern match
if (preg_match($pattern, $v)){
// we found a match, record it
$last = $c;
}
// increment place holder
$c++;
}
// if we found a match, return up until the last match
// if we didn't find one, return what was passed in
return $last != -1 ? array_slice($ary, 0, $last + 1) : $ary;
}
My original answer has a $limit
argument that served no purpose. 我最初的答案有一个
$limit
参数,没有任何作用。 I did originally have a different direction I was going to go with the solution, but decided to keep it simple. 我原本有一个与解决方案一起使用的不同方向,但决定保持其简单性。 However, below is the version that implements that
$limit
. 但是,下面是实现该
$limit
的版本 。 So... 所以...
function split_by_contents($ary, $pattern, $limit = 0){
// really simple error checking
if (!is_array($ary)) return FALSE;
// track the location of the last match, the index of the
// element we're on, and how many matches we have found
$last = -1; $c = 0; $matches = 0;
// iterate over all items (use foreach to keep key integrity)
foreach ($ary as $k => $v){
// text for a pattern match
if (preg_match($pattern, $v)){
// record the last position of a match
$last = $c;
// if there is a specified limit, capture up until
// $limit number of matches, then exit the loop
// and return what we have
if ($limit > 0 && ++$matches == $limit){
break;
}
}
// increment position counter
$c++;
}
I think the easiest way might be with a foreach loop, then using a regex against each value - happy to be proven wrong though! 我认为最简单的方法可能是使用foreach循环,然后对每个值使用正则表达式-但是很高兴被证明是错误的!
One alternative could be to implode the array first... 一种选择是先破坏阵列...
$array = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc","AaDa"...);
$string = implode('~~',$array);
//Some regex to split the string up as you want, guessing something like
// '!~~A.C.~~!' will match just what you want?
$result = explode('~~',$string);
If you'd like a hand with the regex I can do, just not 100% on exactly what you're asking - the "A*C*"-->"AaCc"
bit I'm not too sure on? 如果您想使用我可以做的正则表达式,就不能完全按照您的要求进行100%的操作-
"A*C*"-->"AaCc"
位我不太确定吗?
Assuming incremental numeric indices starting from 0 假设增量数字索引从0开始
$array = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc","AaDa");
$str = "AC";
$regexpSearch = '/^'.implode('.',str_split($str)).'.$/';
$slicedArray = array_slice($array,
0,
array_pop(array_keys(array_filter($array,
function($entry) use ($regexpSearch) {
return preg_match($regexpSearch,$entry);
}
)
)
)+1
);
var_dump($slicedArray);
PHP >= 5.3.0 and will give a PHP> = 5.3.0,将给出一个
Strict standards: Only variables should be passed by reference
严格的标准:只能通过引用传递变量
And if no match is found, will still return the first element. 并且如果找不到匹配项,仍将返回第一个元素。
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