PHP：如何获取具有多个数字的字符串的数值？

Question

Let's say in PHP I have a string-variable : "This takes between 5 and 7 days"

I need to store some sensible information about the time it takes in an integer.

I'm satisfied if the result would be 5.

I tried stripping non-numeric characters, but end up with 57 then.

How can this be done in a better way?

Answer 1

Use preg_match to match the first digit group using a regex:

$subject = 'This takes between 5 and 7 days';
if (preg_match('/\d+/', $subject, $matches)) {
    echo 'First number is: ' . $matches[0];
} else {
    echo 'No number found';
}

Using preg_match_all you could match all digit groups (5 and 7 in this example):

$subject = 'This takes between 5 and 7 days';
if (preg_match_all('/\d+/', $subject, $matches)) {
    echo 'Matches found:<br />';
    print_r($matches);
} else {
    echo 'No number found';
}