blocks|key|185022|text|从PHP5.5开始，您可以使用array_column来获取特定键的值数组，并将其设为最大值。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|185023|max(array_column($array,+'Total'))|style|CODE|185024|entityMap|0|LINK|mutability|MUTABLE|url|https://www.php.net/manual/en/function.array-column.php^0|F|C|0|0|0|Y|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@$A|U|B|V|F|G]]|9|@]|C|$]]|$1|H|3|-4|5|6|7|W|8|@]|9|@]|C|$]]]|I|$J|$5|K|L|M|C|$N|O]]]]

Since PHP 5.5 you can use <a href="https://www.php.net/manual/en/function.array-column.php" rel="noreferrer">array_column</a> to get an array of values for specific key, and max it.
<code>max(array_column($array, 'Total'))</code>

blocks|key|3012599|text|只需执行simple+loop并比较值或使用array_reduce|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3012600|$data+=+array_reduce($data,+function+($a,+$b)+{
++++return+@$a['Total']+>+$b['Total']+?+$a+:+$b+;
});

print_r($data);|code-block|syntax|javascript|3012601|See+Live+Demo|3012602|entityMap|0|LINK|mutability|MUTABLE|url|https://eval.in/35173^0|4|B|M|C|0|0|0|D|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|D|@$9|11|A|12|1|13]]|E|$]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

Just do a <code>simple loop</code> and compare values or use <code>array_reduce</code>

<pre><code>$data = array_reduce($data, function ($a, $b) {
 return @$a['Total'] &gt; $b['Total'] ? $a : $b ;
});

print_r($data);
</code></pre>

<a href="https://eval.in/35173">See Live Demo</a>

blocks|key|3012619|text|这是非常基本的算法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3012620|$max+=+-9999999;+//will+hold+max+val
$found_item+=+null;+//will+hold+item+with+max+val;

foreach($arr+as+$k=>$v)
{
++++if($v['Total']>$max)
++++{
+++++++$max+=+$v['Total'];
+++++++$found_item+=+$v;
++++}
}

echo+"max+value+is+$max";
print_r($found_item);|code-block|syntax|javascript|3012621|Working+demo|offset|length|3012622|entityMap|0|LINK|mutability|MUTABLE|url|http://phpfiddle.org/main/code/k2b-6xp^0|0|0|0|C|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

It's so basic algorithm. 

<pre><code>$max = -9999999; //will hold max val
$found_item = null; //will hold item with max val;

foreach($arr as $k=&gt;$v)
{
 if($v['Total']&gt;$max)
 {
 $max = $v['Total'];
 $found_item = $v;
 }
}

echo "max value is $max";
print_r($found_item);
</code></pre>

<a href="http://phpfiddle.org/main/code/k2b-6xp" rel="noreferrer">Working demo</a>

blocks|key|182704|text|我知道这个问题很老，但我提供以下答案来回答另一个问题，该问题在标记为重复后指向此处。这是另一个我在当前答案中没有提到的选择。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|182705|我知道有一个叫|182706|的函数，但它不适用于这样的多维数组。|blockquote|182707|182708|182709|你可以用array_column解决这个问题，这使得获取最大值变得非常容易：|offset|length|style|CODE|182710|$arr+=+[['message_id'+=>+1,
+++++++++++++'points'+=>+3],
++++++++['message_id'+=>+2,
+++++++++++++'points'+=>+2],
++++++++['message_id'+=>+3,
+++++++++++++'points'+=>+2]];

//+max+value
$max+=+max(array_column($arr,+'points'));|code-block|syntax|javascript|182711|考虑到您实际上可能需要多个键(如果$max匹配多个值)，获取关联键就有点棘手了。您可以使用array_map中的匿名函数来执行此操作，并使用array_filter删除null值：|182712|//+keys+of+max+value
$keys+=+array_filter(array_map(function+($arr)+use+($max)+{
++++return+$arr['points']+==+$max+?+$arr['message_id']+:+null;
},+$arr));|182713|输出：|BOLD|182714|array(1)+{
++[0]=>
++int(1)
}|182715|如果您最终得到了多个键，但只对找到的第一个匹配感兴趣，那么只需引用$keys[0]。|182716|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/array_column|1|http://php.net/array_map|2|http://php.net/array_filter^0|0|0|0|0|0|4|C|4|C|0|0|0|H|4|19|9|1Y|C|2C|4|19|9|1|1Y|C|2|0|0|0|3|0|0|X|8|0^^$0|@$1|2|3|4|5|6|7|1G|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1H|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1I|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|1J|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|1K|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|1L|8|@$K|1M|L|1N|M|N]]|9|@$K|1O|L|1P|1|1Q]]|A|$]]|$1|O|3|P|5|Q|7|1R|8|@]|9|@]|A|$R|S]]|$1|T|3|U|5|6|7|1S|8|@$K|1T|L|1U|M|N]|$K|1V|L|1W|M|N]|$K|1X|L|1Y|M|N]|$K|1Z|L|20|M|N]]|9|@$K|21|L|22|1|23]|$K|24|L|25|1|26]]|A|$]]|$1|V|3|W|5|Q|7|27|8|@]|9|@]|A|$R|S]]|$1|X|3|Y|5|6|7|28|8|@$K|29|L|2A|M|Z]]|9|@]|A|$]]|$1|10|3|11|5|Q|7|2B|8|@]|9|@]|A|$R|S]]|$1|12|3|13|5|6|7|2C|8|@$K|2D|L|2E|M|N]]|9|@]|A|$]]|$1|14|3|-4|5|6|7|2F|8|@]|9|@]|A|$]]]|15|$16|$5|17|18|19|A|$1A|1B]]|1C|$5|17|18|19|A|$1A|1D]]|1E|$5|17|18|19|A|$1A|1F]]]]

I know this question is old, but I'm providing the following answer in response to another question that pointed here after being marked as a duplicate. This is another alternative I don't see mentioned in the current answers.

<blockquote>
 I know there's a function called max but that doesn't work with a multidimensional array like this.
</blockquote>

You can get around that with <a href="http://php.net/array_column" rel="noreferrer"><code>array_column</code></a> which makes getting the maximum value very easy:

<pre><code>$arr = [['message_id' =&gt; 1,
 'points' =&gt; 3],
 ['message_id' =&gt; 2,
 'points' =&gt; 2],
 ['message_id' =&gt; 3,
 'points' =&gt; 2]];

// max value
$max = max(array_column($arr, 'points'));
</code></pre>

Getting the associative key is where it gets a little more tricky, considering that you might actually want multiple keys (if <code>$max</code> matches more than one value). You can do this with an anonymous function inside <a href="http://php.net/array_map" rel="noreferrer"><code>array_map</code></a>, and use <a href="http://php.net/array_filter" rel="noreferrer"><code>array_filter</code></a> to remove the <code>null</code> values:

<pre><code>// keys of max value
$keys = array_filter(array_map(function ($arr) use ($max) {
 return $arr['points'] == $max ? $arr['message_id'] : null;
}, $arr));
</code></pre>

Output:

<pre><code>array(1) {
 [0]=&gt;
 int(1)
}
</code></pre>

If you do end up with multiples keys but are only interested in the first match found, then simply reference <code>$keys[0]</code>.

blocks|key|185018|text|另一种简单的方法是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|185019|$max++=+array_map(+function(+$arr+)+{
++global+$last;
++return+(int)(+(+$arr["Total"]+>+$last+)+?+$arr["Total"]+:+$last+);
},+$array+);

print_r(+max(+$max+)+);|code-block|syntax|javascript|185020|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

another simple method will be

<pre><code>$max = array_map( function( $arr ) {
 global $last;
 return (int)( ( $arr["Total"] &gt; $last ) ? $arr["Total"] : $last );
}, $array );

print_r( max( $max ) );
</code></pre>

blocks|key|182718|text|<?php
$myarray+=+array(
++++0+=>+array(
++++++++'Key1'+=>+'Key1',
++++++++'Total'+=>+13,
++++),
++++1+=>+array(
++++++++'Key2'+=>+'Key2',
++++++++'Total'+=>+117,
++++),
++++2+=>+array(
++++++++'Key2'+=>+'Key3',
++++++++'Total'+=>+39,
++++),
);

$out+=+array();
foreach+($myarray+as+$item)+{
++++$out[]+=+$item['Total'];
}

echo+max($out);+//117

unset($out,+$item);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|182719|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>&lt;?php
$myarray = array(
 0 =&gt; array(
 'Key1' =&gt; 'Key1',
 'Total' =&gt; 13,
 ),
 1 =&gt; array(
 'Key2' =&gt; 'Key2',
 'Total' =&gt; 117,
 ),
 2 =&gt; array(
 'Key2' =&gt; 'Key3',
 'Total' =&gt; 39,
 ),
);

$out = array();
foreach ($myarray as $item) {
 $out[] = $item['Total'];
}

echo max($out); //117

unset($out, $item);
</code></pre>

blocks|key|2800331|text|你可以使用php+usort函数：http://php.net/manual/en/function.usort.php|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2800332|这里给出了一个很好的说明性示例：|2800333|<?php
function+cmp($a,+$b)
{
+return+strcmp($a["fruit"],+$b["fruit"]);
}

$fruits[0]["fruit"]+=+"lemons";
$fruits[1]["fruit"]+=+"apples";
$fruits[2]["fruit"]+=+"grapes";

usort($fruits,+"cmp");

while+(list($key,+$value)+=+each($fruits))+{
+echo+"\$fruits[$key]:+"+.+$value["fruit"]+.+"\n";
}
?>|code-block|syntax|javascript|2800334|因此，它会将最大值排序到最后一个数组索引。|2800335|输出：|2800336|$fruits[0]:+apples
$fruits[1]:+grapes
$fruits[2]:+lemons|2800337|在上面的链接中给出了这个例子|2800338|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.usort.php^0|H|17|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|D|3|E|5|6|7|14|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|15|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|16|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|17|8|@]|9|@]|C|$]]|$1|O|3|P|5|H|7|18|8|@]|9|@]|C|$I|J]]|$1|Q|3|R|5|6|7|19|8|@]|9|@]|C|$]]|$1|S|3|-4|5|6|7|1A|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]]]

You can use php usort function:
<a href="http://php.net/manual/en/function.usort.php" rel="nofollow noreferrer">http://php.net/manual/en/function.usort.php</a>

A pretty illustrative example is given here:

<pre><code>&lt;?php
function cmp($a, $b)
{
 return strcmp($a["fruit"], $b["fruit"]);
}

$fruits[0]["fruit"] = "lemons";
$fruits[1]["fruit"] = "apples";
$fruits[2]["fruit"] = "grapes";

usort($fruits, "cmp");

while (list($key, $value) = each($fruits)) {
 echo "\$fruits[$key]: " . $value["fruit"] . "\n";
}
?&gt;
</code></pre>

So it will sort the max value to the last array index.

Output:

<pre><code>$fruits[0]: apples
$fruits[1]: grapes
$fruits[2]: lemons
</code></pre>

This example is given on aforementioned link

blocks|key|3012657|text|可以使用array_walk(如果需要，使用array_walk_recursive)来完成|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3012658|$arr是要搜索的数组|3012659|$largestElement+=+null;

array_walk($arr,+function(&$item,+$key)+use+(&$largestElement)+{
++++if+(!is_array($largestElement)+%7C%7C+$largestElement["Total"]+<+$item["Total"])+{
++++++++$largestElement+=+$item;
++++}
});|code-block|syntax|javascript|3012660|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Can be done using array_walk(array_walk_recursive if needed)

$arr is the array you want to search in

<pre><code>$largestElement = null;

array_walk($arr, function(&amp;$item, $key) use (&amp;$largestElement) {
 if (!is_array($largestElement) || $largestElement["Total"] &lt; $item["Total"]) {
 $largestElement = $item;
 }
});
</code></pre>

blocks|key|3012662|text|array_reduce接受第三个“初始”参数。使用此命令可以避免使用"@“错误抑制的不良做法：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3012663|$data+=+array_reduce($data,+function+($a,+$b)+{
++++return+$a['Total']+>+$b['Total']+?+$a+:+$b+;
},['Total'+=>+0]);

print_r($data);|code-block|syntax|javascript|3012664|PHP7.4|style|BOLD|3012665|$data+=+array_reduce($data,+fn(a,b)+=>+$a['Total']+>+$b['Total']+?+$a+:+$b,+['Total'+=>+0]);|3012666|entityMap|0|LINK|mutability|MUTABLE|url|https://www.php.net/manual/en/function.array-reduce.php^0|0|C|0|0|0|0|6|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@$A|12|B|13|K|L]]|9|@]|C|$]]|$1|M|3|N|5|F|7|14|8|@]|9|@]|C|$G|H]]|$1|O|3|-4|5|6|7|15|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

<a href="https://www.php.net/manual/en/function.array-reduce.php" rel="nofollow noreferrer">array_reduce</a> accepts a 3rd "initial" parameter. Use this to avoid the bad practice of using "@" error suppression : 

<pre><code>$data = array_reduce($data, function ($a, $b) {
 return $a['Total'] &gt; $b['Total'] ? $a : $b ;
},['Total' =&gt; 0]);

print_r($data);
</code></pre>

PHP 7.4

<pre><code>$data = array_reduce($data, fn(a,b) =&gt; $a['Total'] &gt; $b['Total'] ? $a : $b, ['Total' =&gt; 0]);
</code></pre>

The Problem

I have a multidimensional array similar to the one below. What I'm trying to achieve is a way to find and retrieve from the array the one with the highest "Total" value, now I know there's a function called <code>max</code> but that doesn't work with a multidimensional array like this.

What I've thought about doing is creating a foreach loop and building a new array with only the totals, then using <code>max</code> to find the max value, which would work, the only issue would then be retrieving the rest of the data which relates to that max value. I'm not sure that's the most efficient way either.

Any ideas?

<pre><code>Array
(
 [0] =&gt; Array
 (
 [Key1] =&gt; Key1
 [Total] =&gt; 13
 )

 [1] =&gt; Array
 (
 [Key2] =&gt; Key2
 [Total] =&gt; 117
 )

 [2] =&gt; Array
 (
 [Key3] =&gt; Key3
 [Total] =&gt; 39
 )
)
</code></pre>

Find highest value in multidimensional array

The Problem我有一个类似于下面的多维数组。我正在尝试实现的是一种从数组中查找和检索具有最高"Total“值的数组的方法，现在我知道有一个名为max的函数，但它不适用于这样的多维数组。我想要做的是创建一个foreach循环，创建一个只包含总数的新数组，然后使用max找到最大值，这将会起作用，然后唯一的问题将是检索与该最大值相关的其余数据。我也不确定这是不是最有效的方法。有什么想法吗？Arr

问在多维数组中查找最大值
EN

回答 9

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