从字符串中提取5或6位数字

寻找和一个范围量词应该做到这一点。

模式逻辑说找到一个5或6位数字的序列,然后在匹配的数字前后查找,以确保两边都没有数字。

代码(代码) Demo )

$strings = [
    "21-114512",
    "test12345abcd",
    "12test123456testing",
    "123456",
    "1234",
    "12345a67890"
];
function extract_numbers($string)
{
   return preg_match_all('/(?<!\d)\d{5,6}(?!\d)/', $string, $match) ? $match[0] : [];
}
foreach ($strings as $string) {
    var_export(extract_numbers($string));
    echo "\n---\n";
}

输出:

array (
  0 => '114512',
)
---
array (
  0 => '12345',
)
---
array (
  0 => '123456',
)
---
array (
  0 => '123456',
)
---
array (
)
---
array (
  0 => '12345',
  1 => '67890',
)
---