php - 从包含模式的字符串中提取数字

Question

我有一个像这样的字符串

4-1,4-1,,,1-1,,5-4,2-1,

我需要提取每对中的第一个数字。例如，（ 4 -1， 4 -1 ,,, 1 - 1 ,, 5 - 4 ， 2 -1，）

有谁知道我怎么能做到这一点？

Answer 1

$string = '4-1,4-1,,,1-1,,5-4,2-1,';

preg_match_all('/(\d+)-/', $string, $matches);
// search for 1 or more digits that are followed by a hyphen, and return all matches

print_r($matches[1]);

输出：

Array
(
    [0] => 4
    [1] => 4
    [2] => 1
    [3] => 5
    [4] => 2
)

Answer 2

$couples = explode(",", $data);
$values = Array();

foreach ($couples as $couple)
{
    if ($couple != "")
    {
        $split = explode("-", $couple);
        $values[] = $split[0];
    }
}