从索引数组中获取多维数组的最佳方法[重复]

此函数与接受的答案相同，另外通过引用添加第三个参数，如果密钥存在，则设置为true / false

    
      function drupal_array_get_nested_value(array &$array, array $parents, &$key_exists = NULL) {
  $ref = &$array;
  foreach ($parents as $parent) {
    if (is_array($ref) && array_key_exists($parent, $ref)) {
      $ref = &$ref[$parent];
    }
    else {
      $key_exists = FALSE;
      $null = NULL;
      return $null;
    }
  }
  $key_exists = TRUE;
  return $ref;
}
</code>
  

我有一个我经常使用的实用程序，我会分享。不同之处在于它使用数组访问符号（例如

b[x][z]

）而不是点符号（例如

b.x.z

）。使用文档和代码，它是相当不言自明的。

    
      <?php
class Utils {
    /**
 * Gets the value from input based on path.
 * Handles objects, arrays and scalars. Nesting can be mixed.
 * E.g.: $input->a->b->c = 'val' or $input['a']['b']['c'] = 'val' will
 * return "val" with path "a[b][c]".
 * @see Utils::arrayParsePath
 * @param mixed $input
 * @param string $path
 * @param mixed $default Optional default value to return on failure (null)
 * @return NULL|mixed NULL on failure, or the value on success (which may also be NULL)
 */
public static function getValueByPath($input,$path,$default=null) {
    if ( !(isset($input) && (static::isIterable($input) || is_scalar($input))) ) {
        return $default; // null already or we can't deal with this, return early
    }
    $pathArray = static::arrayParsePath($path);
    $last = &$input;
    foreach ( $pathArray as $key ) {
        if ( is_object($last) && property_exists($last,$key) ) {
            $last = &$last->$key;
        } else if ( (is_scalar($last) || is_array($last)) && isset($last[$key]) ) {
            $last = &$last[$key];
        } else {
            return $default;
        }
    }
    return $last;
}
/**
 * Parses an array path like a[b][c] into a lookup array like array('a','b','c')
 * @param string $path
 * @return array
 */
public static function arrayParsePath($path) {
    preg_match_all('/\\[([^[]*)]/',$path,$matches);
    if ( isset($matches[1]) ) {
        $matches = $matches[1];
    } else {
        $matches = array();
    }
    preg_match('/^([^[]+)/',$path,$name);
    if ( isset($name[1]) ) {
        array_unshift($matches,$name[1]);
    } else {
        $matches = array();
    }
    return $matches;
}
/**
 * Check if a value/object/something is iterable/traversable, 
 * e.g. can it be run through a foreach? 
 * Tests for a scalar array (is_array), an instance of Traversable, and 
 * and instance of stdClass
 * @param mixed $value
 * @return boolean
 */
public static function isIterable($value) {
    return is_array($value) || $value instanceof Traversable || $value instanceof stdClass;
}
}
$arr = array(‘a’ => 1,
             ‘b’ => array(
                 ‘y’ => 2,
                 ‘x’ => array(‘z’ => 5, ‘w’ => ‘abc’)
             ),
             ‘c’ => null);
$key = ‘b[x][z]’;
var_dump(Utils::getValueByPath($arr,$key)); // int 5
?>
</code>
  

作为一个“吸气者”，我过去曾用过这个：

    
      $array = array(‘data’ => array(‘one’ => ‘first’, ‘two’ => ‘second’));
$key = ‘data.one’;
function find($key, $array) {
    $parts = explode(‘.’, $key);
    foreach ($parts as $part) {
        $array = $array[$part];
    }
    return $array;
}
$result = find($key, $array);
var_dump($result);
</code>
  

我有一个非常简单和肮脏的解决方案（
的
真脏！如果密钥的值不受信任，请勿使用！
</强>
）。它可能比循环遍历数组更有效。

    
      function array_get($key, $array) {
    return eval(‘return $array[“‘ . str_replace(‘.’, ‘“][“‘, $key) . ‘“];’);
}
function array_set($key, &$array, $value=null) {
    eval(‘$array[“‘ . str_replace(‘.’, ‘“][“‘, $key) . ‘“] = $value;’);
}
</code>
  

如果数组的键是唯一的，您可以使用几行代码解决问题

array_walk_recursive

：

    
          $arr = array(‘a’ => 1,
        ‘b’ => array(
            ‘y’ => 2,
            ‘x’ => array(‘z’ => 5, ‘w’ => ‘abc’)
        ),
        ‘c’ => null);
function changeVal(&$v, $key, $mydata) {
    if($key == $mydata[0]) {
        $v = $mydata[1];
    }
}
$key = 'z';
$value = '56';
array_walk_recursive($arr, 'changeVal', array($key, $value));
print_r($arr);
</code>