数组 函数

参见

参考 is_array(), explode(), implode(), split(), preg_split(), and unset().

Table of Contents

  • array_change_key_case — 将数组中的所有键名修改为全大写或小写
  • array_chunk — 将一个数组分割成多个
  • array_column — 返回数组中指定的一列
  • array_combine — 创建一个数组，用一个数组的值作为其键名，另一个数组的值作为其值
  • array_count_values — 统计数组中所有的值
  • array_diff_assoc — 带索引检查计算数组的差集
  • array_diff_key — 使用键名比较计算数组的差集
  • array_diff_uassoc — 用用户提供的回调函数做索引检查来计算数组的差集
  • array_diff_ukey — 用回调函数对键名比较计算数组的差集
  • array_diff — 计算数组的差集
  • array_fill_keys — 使用指定的键和值填充数组
  • array_fill — 用给定的值填充数组
  • array_filter — 用回调函数过滤数组中的单元
  • array_flip — 交换数组中的键和值
  • array_intersect_assoc — 带索引检查计算数组的交集
  • array_intersect_key — 使用键名比较计算数组的交集
  • array_intersect_uassoc — 带索引检查计算数组的交集，用回调函数比较索引
  • array_intersect_ukey — 用回调函数比较键名来计算数组的交集
  • array_intersect — 计算数组的交集
  • array_key_exists — 检查数组里是否有指定的键名或索引
  • array_keys — 返回数组中部分的或所有的键名
  • array_map — 为数组的每个元素应用回调函数
  • array_merge_recursive — 递归地合并一个或多个数组
  • array_merge — 合并一个或多个数组
  • array_multisort — 对多个数组或多维数组进行排序
  • array_pad — 以指定长度将一个值填充进数组
  • array_pop — 弹出数组最后一个单元（出栈）
  • array_product — 计算数组中所有值的乘积
  • array_push — 将一个或多个单元压入数组的末尾（入栈）
  • array_rand — 从数组中随机取出一个或多个单元
  • array_reduce — 用回调函数迭代地将数组简化为单一的值
  • array_replace_recursive — 使用传递的数组递归替换第一个数组的元素
  • array_replace — 使用传递的数组替换第一个数组的元素
  • array_reverse — 返回单元顺序相反的数组
  • array_search — 在数组中搜索给定的值，如果成功则返回首个相应的键名
  • array_shift — 将数组开头的单元移出数组
  • array_slice — 从数组中取出一段
  • array_splice — 去掉数组中的某一部分并用其它值取代
  • array_sum — 对数组中所有值求和
  • array_udiff_assoc — 带索引检查计算数组的差集，用回调函数比较数据
  • array_udiff_uassoc — 带索引检查计算数组的差集，用回调函数比较数据和索引
  • array_udiff — 用回调函数比较数据来计算数组的差集
  • array_uintersect_assoc — 带索引检查计算数组的交集，用回调函数比较数据
  • array_uintersect_uassoc — 带索引检查计算数组的交集，用单独的回调函数比较数据和索引
  • array_uintersect — 计算数组的交集，用回调函数比较数据
  • array_unique — 移除数组中重复的值
  • array_unshift — 在数组开头插入一个或多个单元
  • array_values — 返回数组中所有的值
  • array_walk_recursive — 对数组中的每个成员递归地应用用户函数
  • array_walk — 使用用户自定义函数对数组中的每个元素做回调处理
  • array — 新建一个数组
  • arsort — 对数组进行逆向排序并保持索引关系
  • asort — 对数组进行排序并保持索引关系
  • compact — 建立一个数组，包括变量名和它们的值
  • count — 计算数组中的单元数目，或对象中的属性个数
  • current — 返回数组中的当前单元
  • each — 返回数组中当前的键／值对并将数组指针向前移动一步
  • end — 将数组的内部指针指向最后一个单元
  • extract — 从数组中将变量导入到当前的符号表
  • in_array — 检查数组中是否存在某个值
  • key_exists — 别名 array_key_exists
  • key — 从关联数组中取得键名
  • krsort — 对数组按照键名逆向排序
  • ksort — 对数组按照键名排序
  • list — 把数组中的值赋给一组变量
  • natcasesort — 用“自然排序”算法对数组进行不区分大小写字母的排序
  • natsort — 用“自然排序”算法对数组排序
  • next — 将数组中的内部指针向前移动一位
  • pos — current 的别名
  • prev — 将数组的内部指针倒回一位
  • range — 根据范围创建数组，包含指定的元素
  • reset — 将数组的内部指针指向第一个单元
  • rsort — 对数组逆向排序
  • shuffle — 打乱数组
  • sizeof — count 的别名
  • sort — 对数组排序
  • uasort — 使用用户自定义的比较函数对数组中的值进行排序并保持索引关联
  • uksort — 使用用户自定义的比较函数对数组中的键名进行排序
  • usort — 使用用户自定义的比较函数对数组中的值进行排序

User Contributed Notes

DamianKaelGreen at gmail dot com 06-May-2017 01:42
While there are a lot of array functions in the PHP libs, there also seem to be a lot of rudimentary ones missing.

I went ahead and created several of my own functions for handling multiple non-associative (na) arrays including:

na_array_merge
na_array_intersect
na_array_diff
na_array_xnor
na_array_xor

If you are using Venn diagrams to think about your arrays, then these functions might be for you.

I have made them available and posted documentation for them here: https://www.greendingle.com/some-useful-non-associative-array-functions/
Ewan 28-Feb-2017 07:49
I was looking for an array aggregation function here and ended up writing this one.

Note: This implementation assumes that none of the fields you're aggregating on contain The '@' symbol.

<?php
  function array_group_by($flds, $arr) {
    $groups = array();
    foreach ($arr as $rec) {
      $keys = array_map(function($f) use($rec) { return $rec[$f]; }, $flds);
      $k = implode('@', $keys);
      if (isset($groups[$k])) {
        $groups[$k][] = $rec;
      } else {
        $groups[$k] = array($rec);
      }
    }
    return $groups;
  }

?>
nicoolasens at gmail dot com 06-Nov-2015 07:15
/*to change an index without rewriting the whole table and leave at the same place.
*/
<?php
function change_index(&$tableau, $old_key, $new_key) {
    $changed = FALSE;
    $temp = 0;
    foreach ($tableau as $key => $value) {
        switch ($changed) {
            case FALSE :
                //creates the new key and deletes the old
                if ($key == $old_key) {
                    $tableau[$new_key] = $tableau[$old_key];
                    unset($tableau[$old_key]);
                    $changed = TRUE;
                }
                break;

            case TRUE :
                //moves following keys
                if ($key != $new_key){
                $temp= $tableau[$key];
                unset($tableau[$key]);
                $tableau[$key] = $temp;
                break;
                }
                else {$changed = FALSE;} //stop
        }
    }
    array_values($tableau); //free_memory
}

//Result :
$tableau = array(1, 2 , 3, 4,5, 6, 7, 8, 9, 10);
$res = print_r($tableau, TRUE);
$longueur = strlen($res) -1;
echo "Old array :\n" . substr($res, 8, $longueur) . "\n" ;

change_index ($tableau, 2, 'number 2');
$res = print_r($tableau, TRUE);
$longueur = strlen($res) -10;
echo "New array :\n" . substr($res, 8, $longueur) . "\n" ;

/*
Old array :
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
    [6] => 7
    [7] => 8
    [8] => 9
    [9] => 10
)

New array :
    [0] => 1
    [1] => 2
    [numéro 2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
    [6] => 7
    [7] => 8
    [8] => 9
    [9] => 10
*/
?>
callmeanaguma at gmail dot com 18-Jan-2013 08:30
If you need to flattern two-dismensional array with single values assoc subarrays, you could use this function:

<?php
function arrayFlatten($array) {
        $flattern = array();
        foreach ($array as $key => $value){
            $new_key = array_keys($value);
            $flattern[] = $value[$new_key[0]];
        }
        return $flattern;
}
?>
kolkabes at googlemail dot com 05-May-2012 09:31
Short function for making a recursive array copy while cloning objects on the way.

<?php
function arrayCopy( array $array ) {
        $result = array();
        foreach( $array as $key => $val ) {
            if( is_array( $val ) ) {
                $result[$key] = arrayCopy( $val );
            } elseif ( is_object( $val ) ) {
                $result[$key] = clone $val;
            } else {
                $result[$key] = $val;
            }
        }
        return $result;
}
?>
dave at davidhbrown dot us 24-Sep-2011 08:57
While PHP has well over three-score array functions, array_rotate is strangely missing as of PHP 5.3. Searching online offered several solutions, but the ones I found have defects such as inefficiently looping through the array or ignoring keys.

The following array_rotate() function uses array_merge and array_shift to reliably rotate an array forwards or backwards, preserving keys. If you know you can trust your $array to be an array and $shift to be between 0 and the length of your array, you can skip the function definition and use just the return expression in your code.

<?php
function array_rotate($array, $shift) {
    if(!is_array($array) || !is_numeric($shift)) {
        if(!is_array($array)) error_log(__FUNCTION__.' expects first argument to be array; '.gettype($array).' received.');
        if(!is_numeric($shift)) error_log(__FUNCTION__.' expects second argument to be numeric; '.gettype($shift)." `$shift` received.");
        return $array;
    }
    $shift %= count($array); //we won't try to shift more than one array length
    if($shift < 0) $shift += count($array);//handle negative shifts as positive
    return array_merge(array_slice($array, $shift, NULL, true), array_slice($array, 0, $shift, true));
}
?>
A few simple tests:
<?php
$array=array("foo"=>1,"bar"=>2,"baz"=>3,4,5);

print_r(array_rotate($array, 2));
print_r(array_rotate($array, -2));
print_r(array_rotate($array, count($array)));
print_r(array_rotate($array, "4"));
print_r(array_rotate($array, -9));
?>
oliverSPAMMENOT at e-geek dot com dot au 23-Mar-2010 04:28
Function to pretty print arrays and objects. Detects object recursion and allows setting a maximum depth. Based on arraytostring and u_print_r from the print_r function notes. Should be called like so:

<?php
egvaluetostring($value)   //no max depth, or
egvaluetostring($value, $max_depth)   //max depth set

function egvaluetostring($value, $max_depth, $key = NULL, $depth = 0, $refChain = array()) {
  if($depth > 0)
    $tab = str_repeat("\t", $depth);
  $text .= $tab . ($key !== NULL ? $key . " => " : "");
 
  if (is_array($value) || is_object($value)) {
    $recursion = FALSE;
    if (is_object($value)) {
      foreach ($refChain as $refVal) {
        if ($refVal === $value) {
          $recursion = TRUE;
          break;
        }
      }
      array_push($refChain, $value);
    }
   
    $text .= (is_array($value) ? "array" : "object") . " ( ";
   
    if ($recursion) {
      $text .= "*RECURSION* ";
    }
    elseif (isset($max_depth) && $depth >= $max_depth) {
      $text .= "*MAX DEPTH REACHED* ";
    }
    else {
      if (!empty($value)) {
        $text .= "\n";
        foreach ($value as $child_key => $child_value) {
          $text .= egvaluetostring($child_value, $max_depth, (is_array($value) ? "[" : "") . $child_key . (is_array($value) ? "]" : ""), $depth+1, $refChain) . ",\n";
        }
        $text .= "\n" . $tab;
      }
    }
   
    $text .= ")";
   
    if (is_object($value)) {
      array_pop($refChain);
    }
  }
  else {
    $text .= "$value";
  }

  return $text;
}
?>
renatonascto at gmail dot com 17-Sep-2008 08:11
Big arrays use a lot of memory possibly resulting in memory limit errors. You can reduce memory usage on your script by destroying them as soon as you′re done with them. I was able to get over a few megabytes of memory by simply destroying some variables I didn′t use anymore.
You can view the memory usage/gain by using the funcion memory_get_usage(). Hope this helps!
cyberchrist at futura dot net 15-Oct-2007 03:33
Lately, dealing with databases, I've been finding myself needing to know if one array, $a, is a proper subset of $b.

Mathematically, this is asking (in set theory) [excuse the use of u and n instead of proper Unicode):
 
( A u B ) n ( ~ B )

What this does is it first limits to known values, then looks for anything outside of B but in the union of A and B (which would be those things in A which are not also in B).

If any value exists in this set, then A is NOT a proper subset of B, because a value exists in A but not in B.  For A to be a proper subset, all values in A must be in B.

I'm sure this could easily be done any number of ways but this seems to work for me.  It's not got a lot of error detection such as sterilizing inputs or checking input types.

// bool array_subset( array, array )
// Returns true if $a is a proper subset of $b, returns false otherwise.

function array_subset( $a, $b )
{
    if( count( array_diff( array_merge($a,$b), $b)) == 0 )
        return true;
    else
        return false;
}
mo dot longman at gmail dot com 31-Jul-2007 08:27
to 2g4wx3:
i think better way for this is using JSON, if you have such module in your PHP. See json.org.

to convert JS array to JSON string: arr.toJSONString();
to convert JSON string to PHP array: json_decode($jsonString);

You can also stringify objects, numbers, etc.
ob at babcom dot biz 28-Aug-2006 01:23
Here is a function to find out the maximum depth of a multidimensional array.

<?php
// return depth of given array
// if Array is a string ArrayDepth() will return 0
// usage: int ArrayDepth(array Array)

function ArrayDepth($Array,$DepthCount=-1,$DepthArray=array()) {
  $DepthCount++;
  if (is_array($Array))
    foreach ($Array as $Key => $Value)
      $DepthArray[]=ArrayDepth($Value,$DepthCount);
  else
    return $DepthCount;
  foreach($DepthArray as $Value)
    $Depth=$Value>$Depth?$Value:$Depth;
  return $Depth;
}
?>