我想只从一个字符串中提取5个或6位数字。以下是我已经尝试代码,但它并不如预期。
$str1 = "21-114512"; //it should return 114512
$str2 = "test12345abcd"; //it should return 12345
$str3 = "12test123456testing"; //it should return 123456
function extract_numbers($string)
{
preg_match_all('/\b[^\d]*\d{6}[^\d]*\b/', $string, $match);
return $match[0];
}
print_r(extract_numbers($str1));
Lookarounds和范围量词应该做的伎俩。
图案逻辑表示找到的5个或6位数字的序列,然后看看之前和匹配的数字后,以确保不存在在任一侧上的一个数字。
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',
)
---