PHP数组操作类实例

本文实例讲述了PHP数组操作类。分享给大家供大家参考。具体如下：

class ArrayHelper{
  
  static function removeEmpty(& $arr, $trim = TRUE)
  {
    foreach ($arr as $key => $value)
    {
      if (is_array($value))
      {
 self::removeEmpty($arr[$key]);
      }
      else
      {
 $value = trim($value);
 if ($value == '')
 {
   unset($arr[$key]);
 }
 elseif ($trim)
 {
   $arr[$key] = $value;
 }
      }
    }
  }
  
  static function getCols($arr, $col)
  {
    $ret = array();
    foreach ($arr as $row)
    {
      if (isset($row[$col])) {
 $ret[] = $row[$col];
      }
    }
    return $ret;
  }
  
  static function toHashmap($arr, $keyField, $valueField = NULL)
  {
    $ret = array();
    if ($valueField)
    {
      foreach ($arr as $row)
      {
 $ret[$row[$keyField]] = $row[$valueField];
      }
    }
    else
    {
      foreach ($arr as $row)
      {
 $ret[$row[$keyField]] = $row;
      }
    }
    return $ret;
  }
  
  static function groupBy($arr, $keyField)
  {
    $ret = array();
    foreach ($arr as $row)
    {
      $key = $row[$keyField];
      $ret[$key][] = $row;
    }
    return $ret;
  }
  
  static function toTree($arr, $keyNodeId, $keyParentId = 'parent_id', $keyChildrens = 'childrens', & $refs = NULL)
  {
    $refs = array();
    foreach ($arr as $offset => $row)
    {
      $arr[$offset][$keyChildrens] = array();
      $refs[$row[$keyNodeId]] =& $arr[$offset];
    }
    $tree = array();
    foreach ($arr as $offset => $row)
    {
      $parentId = $row[$keyParentId];
      if ($parentId)
      {
 if (!isset($refs[$parentId]))
 {
   $tree[] =& $arr[$offset];
   continue;
 }
 $parent =& $refs[$parentId];
 $parent[$keyChildrens][] =& $arr[$offset];
      }
      else
      {
 $tree[] =& $arr[$offset];
      }
    }
    return $tree;
  }
  
  static function treeToArray($tree, $keyChildrens = 'childrens')
  {
    $ret = array();
    if (isset($tree[$keyChildrens]) && is_array($tree[$keyChildrens]))
    {
      foreach ($tree[$keyChildrens] as $child)
      {
 $ret = array_merge($ret, self::treeToArray($child, $keyChildrens));
      }
      unset($node[$keyChildrens]);
      $ret[] = $tree;
    }
    else
    {
      $ret[] = $tree;
    }
    return $ret;
  }
  
  static function sortByCol($array, $keyname, $dir = SORT_ASC)
  {
    return self::sortByMultiCols($array, array($keyname => $dir));
  }
  
  static function sortByMultiCols($rowset, $args)
  {
    $sortArray = array();
    $sortRule = '';
    foreach ($args as $sortField => $sortDir)
    {
      foreach ($rowset as $offset => $row)
      {
 $sortArray[$sortField][$offset] = $row[$sortField];
      }
      $sortRule .= '$sortArray['' . $sortField . ''], ' . $sortDir . ', ';
    }
    if (empty($sortArray) || empty($sortRule)) {
      return $rowset;
    }
    eval('array_multisort(' . $sortRule . '$rowset);');
    return $rowset;
  }
}

希望本文所述对大家的php程序设计有所帮助。