PHP method to remove duplicates from a two-dimensional array_php tips

Removing duplicate items from a one-dimensional array in PHP can be done through PHP’s built-in function array_unique(), but PHP’s array_unique function is not applicable to multi-dimensional arrays. How can we remove duplicate items from a two-dimensional array?

The following is a function for you.

//二维数组去掉重复值
function unique_arr($array2D,$stkeep=false,$ndformat=true){
  $joinstr='+++++';
  // 判断是否保留一级数组键 (一级数组键可以为非数字)
  if($stkeep) $stArr = array_keys($array2D);
  // 判断是否保留二级数组键 (所有二级数组键必须相同)
  if($ndformat) $ndArr = array_keys(end($array2D));
  //降维,也可以用implode,将一维数组转换为用逗号连接的字符串
  foreach ($array2D as $v){
    $v = join($joinstr,$v);
    $temp[] = $v;
  }
  //去掉重复的字符串,也就是重复的一维数组
  $temp = array_unique($temp);
  //再将拆开的数组重新组装
  foreach ($temp as $k => $v){
    if($stkeep) $k = $stArr[$k];
    if($ndformat){
      $tempArr = explode($joinstr,$v);
      foreach($tempArr as $ndkey => $ndval) $output[$k][$ndArr[$ndkey]] = $ndval;
    }
    else $output[$k] = explode($joinstr,$v);
  }
  return $output;
}

I hope it will be helpful for everyone to learn PHP programming.