拆分并解析字符串以创建关联数组的数组

Question

如何将以下字符串转换为二维数组？

$coordinates = "9.499819 123.920318,9.490845 123.916563,9.484644 123.922292,9.49148 123.931519,9.499755 123.925683,9.499819 123.920318";

我想用逗号分隔成对的值，然后用分隔空间分隔每对值，形成包含浮点类型值的关联行。

期望输出：

$polygon = array(
array('lat' => 9.499819, 'lng' => 123.920318),
array('lat' => 9.490845, 'lng' => 123.916563),
array('lat' => 9.484644, 'lng' => 123.922292),
array('lat' => 9.49148, 'lng' => 123.931519),
array('lat' => 9.499755, 'lng' => 123.925683),
array('lat' => 9.499819, 'lng' => 123.920318)
);

Answer 1

在我看来，对于一个新的贡献者来说，使用foreach的解决方案更容易理解。代码中对这些步骤进行了注释。

$coordinates = "9.499819 123.920318,9.490845 123.916563,9.484644 123.922292,9.49148 123.931519,9.499755 123.925683,9.499819 123.920318";
$polygon = explode(',',$coordinates);
/*
array (
0 => "9.499819 123.920318",
1 => "9.490845 123.916563",
*/
foreach($polygon as $index => $latLng){
//The element $latLng is split into two variables with list and explode.
list($lat,$lng) = explode(' ',$latLng);
//The elements are replaced by a new array with the variables $lat and $lng as float
$polygon[$index] = ['lat' => (float)$lat, 'lng' => (float)$lng];
}
//test output
echo '<pre>';
var_export($polygon);

输出：

array (
0 => 
array (
'lat' => 9.499819,
'lng' => 123.920318,
),
1 => 
array (
'lat' => 9.490845,
'lng' => 123.916563,
),
2 => 
array (
'lat' => 9.484644,
'lng' => 123.922292,
),
3 => 
array (
'lat' => 9.49148,
'lng' => 123.931519,
),
4 => 
array (
'lat' => 9.499755,
'lng' => 123.925683,
),
5 => 
array (
'lat' => 9.499819,
'lng' => 123.920318,
),
) 

添加2022-03-04:

这个带有preg_match_all的一行已经返回了完整的结果，但带有额外的数字键。

preg_match_all('~(?<lat>[0-9.]+) (?<lng>[0-9.]+),?~', $coordinates, $match,PREG_SET_ORDER);

array_map可以用来去除多余的值。

$polygon = array_map(
function($row){return ['lat' => $row['lat'],'lng' => $row['lng']];},
$match
);

Answer 2

通过对sscanf()进行迭代调用，您可以指定解析值的数据类型，并将值推送到结果数组中。

代码：(演示(

$coordinates = "9.499819 123.920318,9.490845 123.916563,9.484644 123.922292,9.49148 123.931519,9.499755 123.925683,9.499819 123.920318";
foreach (explode(',', $coordinates) as $i => $latLng) {
sscanf($latLng, '%f %f', $result[$i]['lat'], $result[$i]['lng']);
};
var_export($result);

输出：

array (
0 => 
array (
'lat' => 9.499819,
'lng' => 123.920318,
),
1 => 
array (
'lat' => 9.490845,
'lng' => 123.916563,
),
2 => 
array (
'lat' => 9.484644,
'lng' => 123.922292,
),
3 => 
array (
'lat' => 9.49148,
'lng' => 123.931519,
),
4 => 
array (
'lat' => 9.499755,
'lng' => 123.925683,
),
5 => 
array (
'lat' => 9.499819,
'lng' => 123.920318,
),
)