Regular expression for extracting a number

Question

I would like to be able to extract a number from within a string formatted as follows:

\"<[1085674730]> hello foo1, how are you doing?\"

I\'m a novice wit

Answer 1

Combine Mathews post with lookarounds http://www.regular-expressions.info/lookaround.html. This will exclude the prefix and suffix.

(?<=<\[)\d+(?=\]>)

I didn't test this regex but it should be very close to what you need. Double check at the link provided.

Hope this helps!

Answer 2

Use:

<\[(\d+)\]>

This is tested with ECMAScript regex.

It means:

• \[ - literal [
• ( - open capturing group
• \d - digit
• + - one or more
• ) - close capturing group
• \] - literal ]

The overall functionality is to capture one or more digits surrounded by the given characters.

Answer 3

$subject = "<[1085674730]> hello foo1, how are you doing?";
preg_match('/<\[(\d+)\]>/', $subject, $matches);

$matches[1] will contain the number you are looking for.

Answer 4

Use:

/<\[([[:digit:]]+)\]>/

If your implementation doesn't support the handy [:digit:] syntax, then use this:

/<\[([\d]+)\]>/

And if your implementation doesn't support the handy \d syntax, then use this:

/<\[([0-9]+)\]>/