What is the quickest and most code efficient way to pull a number from a NSString?

Question

I have a number of strings like these. The numbers can be infinitely long.

<a href="?page=1">1</a>
<a href="?page=13">13</a>
<a href="?page=13121">13121</a>
<a href="?page=1389988797">1389988797</a>

What is the quickest and most code efficient way to pull JUST the number from these NSStrings?

which number? the one after `>`? – Avinash Raj Aug 30 '14 at 03:30 — Avinash Raj, Aug 30 '14 at 03:30
Yes, the one between the > and – Ethan Allen Aug 30 '14 at 03:36 — Ethan Allen, Aug 30 '14 at 03:36
try this regex `(?<=>)\d+(?=<)` – Avinash Raj Aug 30 '14 at 03:37 — Avinash Raj, Aug 30 '14 at 03:37

score 2 · Answer 1 · answered Aug 30 '14 at 03:42

Well, there are 21 non-number characters in each of your examples, so the length of the numbers will be:

NSUInteger length = (string.length-21)/2;

the location will be:

NSUInteger location = string.length-4-length;

so a quick path to the digits should therefore be:

[string substringWithRange:NSMakeRange(location, length)];

1 Answers1