可能重复：
从多维数组中的元素中获取最大值
在php 中查找特定多维数组值的max（）
我正试图从多维数组中找出最大的数组。
Array
(
[0] => Array
(
[comment] => ayya
[commented_on] => 17/03/12
[ckey] => 210029c5d80d8259d1599c9a
[username] => pappa
[up] => 2
[down] => 0
[vote] => 2
)
[1] => Array
(
[comment] => sdfsd
[commented_on] => 17/03/12
[ckey] => 08f6a34f96bdeef2903ddaf4
[username] => jesse
[up] => 2
[down] => 0
[vote] => 2
)
[2] => Array
(
[comment] => 159
[commented_on] => 17/03/12
[ckey] => 4da385124793336339268782
[username] => jesse
[up] => 2
[down] => 0
[vote] => 2
)
[3] => Array
(
[comment] => s
[commented_on] => 17/03/12
[ckey] => 299c77c52ee087e468e23e82
[username] => jesse
[up] => 2
[down] => 0
[vote] => 2
)
[4] => Array
(
[comment] => jh
[commented_on] => 17/03/12
[ckey] => 523c18820d8b8db827a240ad
[username] => jesse
[up] => 2
[down] => 0
[vote] => 2
)
[5] => Array
(
[comment] => jh
[commented_on] => 17/03/12
[ckey] => 9f824c11b0ecafcc38c09f4c
[username] => jesse
[up] => 1
[down] => 1
[vote] => 0
)
[6] => Array
(
[comment] => jh
[commented_on] => 17/03/12
[ckey] => c97e7ad4d205220c4b8b0332
[username] => jesse
[up] => 1
[down] => 0
[vote] => 1
)
)
我想得到票数最高的数组。最高表示具有最高投票的阵列
我使用了以下代码，但它不起作用。
$large=array();
foreach($final2 as $f1){
foreach($final2 as $f2){
if($f1['vote']>$f2['vote'])
$large=$f1;
}
}
AFAIK数组的大小是根据它所包含的元素数量来计算的。
所以这可能有助于
$largeArraySize = 0;
foreach($arraylist as $array) {
if(count($array) > $largeArraySize) {
$largeArray = $array;
}
}
// Hence $largeArray has the largest
print_r($largeArray);
除非出现一个大数组，否则此代码将以第一次出现为最大值。
由于数组只嵌套一层深，并且所有子数组都有相同的结构，因此只需循环遍历外部数组并跟踪到目前为止看到的最大值。漂亮又简单。
如果没有其他信息，例如数组是否已经根据票数排序，您剩下的唯一选项是O(n)线性搜索。
$max = 0;
$max_index = 0;
if( count($outer_array) > 0 )
{
// There are elements in the outer array
for($i = 0; $i < count($outer_array); $i++ )
{
if( isset($outer_array[$i]["vote"]) )
{
if( $outer_array[$i]["vote"] > $max )
{
$max_index = $i;
}
}
else
{
// Error condition, malformed array
// Do something here, maybe throw exception?
}
}
}
else
{
// Error condition - outer array is empty, could also throw exception here...
$max = -1; // Assume votes cannot be negative
$max_index = -1;
}
if( $max_index != -1 )
{
// Success
// Do something...
}
这应该会让您了解在内部数组中获得最高票数的想法：
$array = array(
array('votes' => 2),
array('votes' => 3),
array('votes' => 0),
array('votes' => 1)
);
$votes = 0;
$key = 0;
for($i = 0; $i < count($array); $i++){
if($array[$i]['votes'] > $votes){
$key = $i;
$votes = $array[$i]['votes'];
}
}
将代码更改为：
$large=array('vote' => -1);
foreach($final2 as $f1){
if ($f1['vote'] > $large['vote']) {
$large=$f1;
}
}
$array = array(.....)
$max_votes = 0;
foreach ($array as $data) {
$vote = $data['vote'];
if ($vote > $max_vote) {
$max_vote = $vote;
}
}
$max = array();
foreach ($array as $key => $data) {
if ($data['vote'] == $max_vote) {
$max[] = $key;
}
}
$max现在将持有所有数组，最高票数为$max_votes值。