array_keys($array) //返回所有键名 
 
array_values($array) //返回所有键值  
 
$result=array_reverse($input); //将数组颠倒，不保留键名 
$result_keyed=array_reverse($input,true); //将数组颠倒，保留键名 
 
array_keys($array,"blue"); //返回值为blue的键名 
 

function unique_arr($array2D,$stkeep=false,$ndformat=true) 
{ 
  // 判断是否保留一级数组键 (一级数组键可以为非数字) 
  if($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){ 
    $v = join(",",$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) 
    { 
      $tempArr = explode(",",$v);  
      foreach($tempArr as $ndkey => $ndval) $output[$k][$ndArr[$ndkey]] = $ndval; 
    } 
    else $output[$k] = explode(",",$v);  
  } 
 
  return $output; 
} 
 

$array2D = array('first'=>array('title'=>'1111','date'=>'2222'),'second'=>array('title'=>'1111','date'=>'2222'),'third'=>array('title'=>'2222','date'=>'3333')); 
 
 
print_r($array2D); 
print_r(unique_arr($array2D,true)); 

function printr($arr) 
{ 
  echo '<pre>';  
  print_r($arr); 
  echo '</pre><br>'; 
} 

$a = array('a'=>1,2);  
sort($a); printr($a);  
rsort($a); printr($a); 
 
/*Array 
( 
  [0] => 1 
  [1] => 2 
) 
 
Array 
( 
  [0] => 2 
  [1] => 1 
) 
*/ 

$a = array('a'=>1,2); 
asort($a); printr($a);   
arsort($a); printr($a);  
/* 
Array 
( 
  [a] => 1 
  [0] => 2 
) 
 
Array 
( 
  [0] => 2 
  [a] => 1 
) 
*/ 

$a = array('a'=>1,2); 
 ksort($a); printr($a);   
krsort($a); printr($a); 
 
/* 
Array 
( 
  [0] => 2 
  [a] => 1 
) 
 
Array 
( 
  [a] => 1 
  [0] => 2 
) 
*/ 

/** 
 * @package   BugFree 
 * @version   $Id: FunctionsMain.inc.php,v 1.32 2005/09/24 11:38:37 wwccss Exp $ 
 * 
 * 
 * Sort an two-dimension array by some level two items use array_multisort() function. 
 * 
 * sortArr($Array,"Key1","SORT_ASC","SORT_RETULAR","Key2"……) 
 * @author           Chunsheng Wang <wwccss@263.net> 
 * @param array  $ArrayData  the array to sort. 
 * @param string $KeyName1  the first item to sort by. 
 * @param string $SortOrder1 the order to sort by("SORT_ASC"|"SORT_DESC") 
 * @param string $SortType1  the sort type("SORT_REGULAR"|"SORT_NUMERIC"|"SORT_STRING") 
 * @return array        sorted array. 
 */ 
function sortArr($ArrayData,$KeyName1,$SortOrder1 = "SORT_ASC",$SortType1 = "SORT_REGULAR") 
{ 
  if(!is_array($ArrayData)) return $ArrayData; 
   
  // Get args number. 
  $ArgCount = func_num_args(); 
  // Get keys to sort by and put them to SortRule array. 
  for($I = 1;$I < $ArgCount;$I ++) 
  { 
    $Arg = func_get_arg($I); 
    if(!eregi("SORT",$Arg)) 
    { 
      $KeyNameList[] = $Arg; 
      $SortRule[]  = '$'.$Arg; 
    } 
    else $SortRule[]  = $Arg; 
  } 
  // Get the values according to the keys and put them to array. 
  foreach($ArrayData AS $Key => $Info) 
  { 
    foreach($KeyNameList AS $KeyName) ${$KeyName}[$Key] = strtolower($Info[$KeyName]); 
  } 
   
  // Create the eval string and eval it. 
  $EvalString = 'array_multisort('.join(",",$SortRule).',$ArrayData);'; 
  eval ($EvalString); 
  return $ArrayData; 
} 

//################# 示例 ################# 
$arr = array( 
 array( 
   'name'    =>  '学习', 
   'size'    =>  '1235', 
   'type'    =>  'jpe', 
   'time'    =>  '1921-11-13', 
   'class'    =>  'dd', 
 ), 
 array( 
   'name'    =>  '中国功夫', 
   'size'    =>  '153', 
   'type'    =>  'jpe', 
   'time'    =>  '2005-11-13', 
   'class'    =>  'jj', 
 ), 
 array( 
   'name'    =>  '编程', 
   'size'    =>  '35', 
   'type'    =>  'gif', 
   'time'    =>  '1997-11-13', 
   'class'    =>  'dd', 
 ), 
 array( 
   'name'    =>  '中国功夫', 
   'size'    =>  '65', 
   'type'    =>  'jpe', 
   'time'    =>  '1925-02-13', 
   'class'    =>  'yy', 
 ), 
 array( 
   'name'    =>  '中国功夫', 
   'size'    =>  '5', 
   'type'    =>  'icon', 
   'time'    =>  '1967-12-13', 
   'class'    =>  'rr', 
 ), 
); 
 
echo '<pre>'; 
print_r($arr); echo '<br>'; 
 
//注意：按照数字方式排序时 153 比 65 小 
$temp = sortArr($arr,"name","SORT_ASC","type","SORT_DESC","size","SORT_ASC","SORT_STRING"); 
 
print_r($temp); 
 
echo '</pre>'; 

function rebuild_array($arr){ //rebuild a array 
 static $tmp=array(); 
 
 for($i=0; $i<count($arr); $i++){ 
  if(is_array($arr[$i])){ 
    rebuild_array($arr[$i]); 
  }else{ 
    $tmp[]=$arr[$i]; 
  } 
 } 
 
 return $tmp; 
} 

$arr=array('123.html','456.html',array('dw.html','fl.html',array('ps.html','fw.html')),'ab.html'); 
 
// 定义一个三维数组，用来检测我们的函数 
echo '<pre>'; 
print_r(rebuild_array($arr)); 
echo '</pre>'; 

function array_remove_empty(&$arr, $trim = true)   
{   
  foreach ($arr as $key => $value) {   
    if (is_array($value)) {   
      array_remove_empty($arr[$key]);   
    } else {   
      $value = trim($value);   
      if ($value == '') {   
        unset($arr[$key]);   
      } elseif ($trim) {   
        $arr[$key] = $value;   
      }  
    }   
  }   
}  

$a = array(array(3),2,'',array('',23),0); 
 
array_remove_empty($a); 
 
printr($a); // printr 函数请在本文中找 

function getall_by_key(array $arr, $key){ 
  if (!trim($key)) return false; 
  preg_match_all("/\"$key\";\w{1}:(", serialize($arr), $output); 
  return $output[1]; 
} 
 
$testArr = array('111'=> 100, 'out'=> 200, '333' => array('out' => 310, array(321, 322, 'out' => "this is a test"))); 
 
printr(getall_by_key($testArr, 'out'));