获取多维数组从元素的最大值？ [英] Get the maximum value from an element in a multidimensional array?

问题描述

我想选择多维数组中特定的键的最大值。我无法进入问题的关键...

因此​​，阵列（这是比我在这里发帖更长时间）

  [0] =＆GT; stdClass的对象
    （
        [ID] =＆GT; 70
        [自定义] =＆GT; 4
        [dnum] =＆GT; 1
        [上] =＆GT;排列
            （
                [0] =＆GT; 66
            ）    ）
[1] =＆GT; stdClass的对象
    （
        [ID] =＆GT; 43
        [自定义] =＆GT; 42
        [dnum] =＆GT; 2
        [上] =＆GT;排列
            （
                [0] =＆GT; 77
            ）    ）
[2] =＆GT; stdClass的对象
    （
        [ID] =＆GT; 12
        [自定义] =＆GT; 3
        [dnum] =＆GT; 0
        [上] =＆GT;排列
            （
                [0] =＆GT; 99
            ）    ）
 

我试图找到整个阵列的最大dnum的价值，所以在这个例子中，$最大= 2。我知道，最大的功能可以让我做这件事，但我不知道如何引用dnum元素没有把整个事情在foreach循环中，如果我这样做，那么最多将不使用的功能，对不对？

所以，我不能确切地做到这一点：

  $最大值= MAX（$ myArray的[]  - ＆GT; dnum）;
 

有没有为我做到这一点，而无需重新创建整个阵列的方式？

解决方案

  $最大= 0;
的foreach（$数组与obj $）
{
    如果（$ obj-＆GT; dnum＆GT; $最大值）
    {
        $最大= $ obj-＆GT; dnum;
    }
}
 

如果你的最高数字是负数，这函数将正常工作。

由于您使用的是一个对象，它可以有自定义属性/结构，我不相信有一个你可以用它来得到它真正的'predefined功能。还不如干脆使用foreach循环。

您真的不能从一个foreach循环了，因为即使是内部功能使用foreach循环，它只是在幕后。

另一个解决方案是

  $号=阵列（）;
的foreach（$数组与obj $）
{
    $编号[] = $ obj-＆GT; dnum;
}
$最大值= MAX（$数）;
 

I'm trying to select the maximum value for a particular key in a multidimensional array. I'm having trouble "getting to" the key in question...

So, the array (which is much more lengthy than what I'm posting here)

[0] => stdClass Object
    (
        [id] => 70
        [cust] => 4
        [dnum] => 1
        [upper] => Array
            (
                [0] => 66
            )

    )
[1] => stdClass Object
    (
        [id] => 43
        [cust] => 42
        [dnum] => 2
        [upper] => Array
            (
                [0] => 77
            )

    )
[2] => stdClass Object
    (
        [id] => 12
        [cust] => 3
        [dnum] => 0
        [upper] => Array
            (
                [0] => 99
            )

    )

I'm trying to find the maximum "dnum" value across the entire array, so in this example, $max = 2. I know that the max function allows me to do this, but I'm not sure how to reference the dnum element without putting the whole thing in a foreach loop, and if I do that, then max wouldn't be the function to use, right?

So, I can't exactly do this:

$max = max($myarray[]->dnum);

Is there a way for me to do this without having to recreate the entire array?

解决方案

$max = 0;
foreach($array as $obj)
{
    if($obj->dnum > $max)
    {
        $max = $obj->dnum;
    }
}

That function would work correctly if your highest number is negative.

Because you are using an object, which can have custom properties/structures, I don't believe there are really any 'predefined' functions you can use to get it. Might as well just use a foreach loop.

You really can't get away from a foreach loop, as even internal functions use a foreach loop, it is just behind the scenes.

Another solution is

$numbers = array();
foreach($array as $obj)
{
    $numbers[] = $obj->dnum;
}
$max = max($numbers);

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