用正則表達式拆分數組

Question

我想知道是否可以通過使用正則表達式截斷數組。

特別是我有一個像這樣的數組：

$array = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc","AaDa"...);

我有這個字符串：

$str = "AC";

我想要從$array的切片開始到最后一個匹配/AC/的字符串（在示例中，索引為5的“ AaCc”）：

$result = array("AaBa","AaBb","AaBc","AaCa","AaCb","AaCc");

我怎樣才能做到這一點？ 我以為可以使用array_slice ，但是我不知道如何使用RegEx。

Answer 1

這是我的出價

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;
}

---

更新

我最初的答案有一個$limit參數，沒有任何作用。 我原本有一個與解決方案一起使用的不同方向，但決定保持其簡單性。 但是，下面是實現該$limit的版本 。 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++;
  }

Answer 2

我認為最簡單的方法可能是使用foreach循環，然后對每個值使用正則表達式-但是很高興被證明是錯誤的！

一種選擇是先破壞陣列...

$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);

如果您想使用我可以做的正則表達式，就不能完全按照您的要求進行100％的操作- "A*C*"-->"AaCc"位我不太確定嗎？

Answer 3

假設增量數字索引從0開始

$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，將給出一個

嚴格的標准：只能通過引用傳遞變量

並且如果找不到匹配項，仍將返回第一個元素。