Php 多维数组中的最小值和最大值

您好，我正在尝试查找x和y的最小值和最大值。我如何才能找到此最小值和最大值函数工作不正常

$dataPoints = array(
 array('x' => 2343, 'y' => 4322),
  array('x' => 103, 'y' => 303 ),
  array('x' => 2345,'y' => 2321 ),
  array('x' => 310, 'y' => 2044 ),
  array('x' => 173, 'y' => 793 ),
  array('x' => 456, 'y' => 2675),
  array('x' => 24, 'y' => 819 ));

---

我认为你必须编写自己的函数：

<?php  
    function max_with_key($array, $key) {
        if (!is_array($array) || count($array) == 0) return false;
        $max = $array[0][$key];
        foreach($array as $a) {
            if($a[$key] > $max) {
                $max = $a[$key];
            }
        }
        return $max;
    }


    $dataPoints = array(
     array('x' => 2343, 'y' => 4322),
      array('x' => 103, 'y' => 303 ),
      array('x' => 2345,'y' => 2321 ),
      array('x' => 310, 'y' => 2044 ),
      array('x' => 173, 'y' => 793 ),
      array('x' => 456, 'y' => 2675),
      array('x' => 24, 'y' => 819 ));

    $max_x = max_with_key($dataPoints, 'x');  //2343
    $max_y = max_with_key($dataPoints, 'y');  //4322
?>

---

尝试以下方法：

foreach($dataPoints as $point) {
    if (!isset($x) || $point['x'] > $x) {
        $x = $point['x'];
    }
    if (!isset($y) || $point['y'] > $y) {
        $y = $point['y'];
    }
}

---

生成所需答案的示例代码

foreach($dataPoints[0]['x'] as $x_val)
{
//write max min func for x values
}

foreach($dataPoints[0]['y'] as $y_val)
{
//write max min func for y values
}

---

我是下划线库的粉丝

不是本机函数，但将避免您自己编写函数，以及许多其他函数：）

哦，它变成了一行

例如：

include_once 'underscore.php';

$dataPoints = array(
    array('x' => 2343, 'y' => 4322),
    array('x' => 103, 'y' => 303 ),
    array('x' => 2345,'y' => 2321 ),
    array('x' => 310, 'y' => 2044 ),
    array('x' => 173, 'y' => 793 ),
    array('x' => 456, 'y' => 2675),
    array('x' => 24, 'y' => 819 )
);


__::max($dataPoints, function($item) { return $item['x']; });    // array('x' => 2345,'y' => 2321 )
__::min($dataPoints, function($item) { return $item['y']; });    // array('x' => 103, 'y' => 303 ) 

您可以使用PHP（PHP5>=5.5.0）实现以下目的：

$min_x = min( array_column( $dataPoints, 'x' ) );
$min_y = min( array_column( $dataPoints, 'y' ) );
$max_x = max( array_column( $dataPoints, 'x' ) );
$max_x = max( array_column( $dataPoints, 'y' ) );

---

通过组合、和函数，可以分别找到每列的最小值和最大值：

$min_x = min(array_column($dataPoints, 'x'));
$max_x = max(array_column($dataPoints, 'x'));
$min_y = min(array_column($dataPoints, 'y'));
$max_y = max(array_column($dataPoints, 'y'));

---

是否有任何方法可以获得具有最大值的数组，而不仅仅是最大值放大镜。但如果您也需要数组密钥，则需要更改foreach以包含该密钥（数组的…因为否则逻辑警察会逮捕您），并更改if如下：

$max[$logicpolice]=$a[$key]记住添加$x=array（）$y=数组（）；在foreach之前。
$min_x = min(array_column($dataPoints, 'x'));
$max_x = max(array_column($dataPoints, 'x'));
$min_y = min(array_column($dataPoints, 'y'));
$max_y = max(array_column($dataPoints, 'y'));